Body at War:Disease:

Diseases are any conditions that affect the normal functioning of the body and can be grouped into two broad categories: Infectious and non-infectious

Infectious Disease:

Are diseases that are contagious (you can catch them from someone else & they can be transferred from one person to another) and they are caused by a pathogen.

Non – Infectious Disease:

Non – infectious diseases are not contagious. You cannot ‘catch’ then from other people. They include heredity diseases such as haemophilia and cystic fibrosis that are passed down in families. Some are diet related, meaning they are caused by eating unbalanced diets or a diet that is deficient in one or more

nutrients. Scurvy, rickets, and heart disease fall in this category. Most cancers are non-infectious diseases, although viruses have been implicated in some cancers (cancer of the cervix) Mental illnesses such as dementia, depression and schizophrenia

Pathogen:

Are organisms which cause diseases. They can be either macroscopic – you can see them without a microscope – However most pathogens can be microscopic, which means you need a microscope to see them. Microscopic Pathogens can be classified into five main groups:

Bacteria:

Single celled organisms whose DNA is not contained inside a membrane bound nucleus Examples: Scarlet fever, meningitis, impetigo, throat and middle ear infections, leprosy

Fungi:

Fungi are made up of one or more cells that have a cell wall, true nucleus and no chloroplasts. Athlete’s foot is caused by fungus. Thrush, ring worm, athlete’s foot

Protozoans:

Single celled organisms whose DNA is contained inside a membrane bound nucleus Malaria, gardia, amoebic dysentery

Viruses:

A virus consists of a piece of DNA or RNA wrapped in a protein coat Viruses cannot reproduce unless inside a host cell

Prions:

Thought to be incorrectly folded proteins Mad cow disease, fatal family insomnia

Balanced Diet:

Diet Deficiency diseases include:

Scurvy : Lack of Vitamin C, Eat foods like red and green peppers, mandarins, oranges, kiwi etc. Effects : tiredness, nausea, cuts and bruises etc

Vitamin A deficiency: Lack of vitamin A, eat liver, meat, carrots, eggs.. Effects: goose bumps, night blindness Rickets: Lack of Vitamin D and Calcium: Eat: Dairy, leafy greens, whole grains. Effects: Brittle bones, thin bones etc Osteoporosis Lack of Vitamin D and Calcium: Eat: Dairy, leafy greens, whole grains. Effects: Brittle bones, thin bones etc Anaemia: lack of Iron, things like meat products, dairy and milk products, tiredness, weight loss, paleness. Potassium Deficiency: Lack of potassium, apricots, raisins, strawberries, banana, muscular weakness, memory loss, kidney

diseases Calcium Deficiency: Lack of calcium, milk products, brittle bones, coarse hair etc

First Line of Defence:

Is designed to prevent the entry of invading pathogens. Some of these defences are physical barriers (such as skin, coughing, sneezing, cilia and nasal hairs) Others are chemical barriers (body fluids such as saliva, tears, stomach acid, and acid vaginal mucus)

Physical Barriers

Skin:

Very effective at keeping out germs. It is waterproof, and unless you have a cut, microbes cannot pass through it. It is dry and slightly acidic; this prevents growth of many bacteria and fungi on the skin. If your skin does become cut, the hole is very quickly patched up. Blood clot forms to seal up the cut, then a scab forms and eventually the skin heals Has an outer; layer of dead skin cells. Surface barrier to most diseases Prevents pathogens from invading your internal organs

Hair and Cilia:

Small hairs that are found in the nose and upper respiratory tract. In the nose they are coasted with mucous, which helps to filter out microbes and particles that have been breathed in. The hairs in the reparatory tract then move these particles to the throat, where they are coughed, or sneezed out of the

body.

Mucous Membranes:

Membranes that line the alimentary canal, the respiratory tract and the urinogenital tract. Also the digestive tract. They secrete various substances that inhibit the growth or pathogens, and can also trap pathogens until the body can get rid

of them. Pathogens get trapped in the mucus so they cannot penetrate tissues.

Chemical Barriers:

These include the anti-microbial secretions of the skin, mucous membranes, stomach wall and vagina. The pH of the stomach and vagina are acidic, helping to reduce the growth of microbes. Body fluids such as tears and saliva contain chemicals that cleanse and wash away pathogens.

Other Body Secretions:

These include the secretion of lysozymes (enzymes that can break bacterial walls) in tears, saliva, and blood serum. Urine is another secretion that inhibits bacterial growth due to its acidity. The secretion of fatty acids from sebaceous glands in the skin also helps to reduce microbial growth.

2 nd line of Defence: Inflammation:

If pathogens make it past the first line of defence they will encounter the body’s second line of defence. The second line of defence involves a process known as phagocytosis .

Phagocytosis: In this process, white blood cells, called phagocytes, engulf the pathogens, trapping them so that they are unable to infect

other parts of the body.Phagocytes:

They are white blood cells that can engulf and destroy bacteria. These include macrophages and neutrophils. After the pathogen has been trapped the white blood cells produce enzymes to destroy it. Your other body systems help the white blood cells by producing inflammation.

Inflammation: This is where the blood vessels around the affected area increase in size so that more phagocytes can reach the area under

attack by the pathogen. Inflammation causes the affected area to become red and swollen.

Pus: May also be produced which contain white blood cells which have died in the process of destroying the pathogens.

Heat: Gives fever – kills germs Helps fight infection Fever – heat burns and kills infection in the body

Blood: Contains Phagocytic white cells Phagocytic white cells = engulf and digest germs in wounds, in the blood stream and infected tissue.

Damaged Cells: Release special chemical substances that make blood flow into inflamed area Special chemicals flow into inflamed area rapidly Sends down a message The Immune System: 3 rd line of Defence: Antibodies form the 3rd line of defence. These are chemicals that bond to the surface of the pathogen stopping the pathogen from functioning properly and

eventually killing it. Each type of pathogen requires a particular type of antibody to destroy it. Each time your body encounters a new pathogen it has to work out which antibody to produce, this takes time and while it

is working this out you get sick. Once it has figured out the required antibody the body remembers this so that next time it encounters the pathogen it

knows exactly what antibody to produce. The Lymphatic System:

Consists of a network of lymph vessels that drain fluid from your tissues into lymph nodes. Makes white blood cells.

Consists of:Spleen: Filters blood and removes cellular debrisLymphatic vessels:Lymph nodes:Bone marrow: generates b-cell lymphocytesGalt: surrounds intestines, counteracts infection and absorbs fatsThymus gland: Generates t-cell lymphocytesThoracic duct: returns cleansed and enriched lymphs to blood supply. Lymph Nodes:

The fluid is filtered to remove foreign material and pathogens before they enter the blood stream. Filter lymph and light infection

Lymphocytes: Special white blood cells that circulate in your blood and lymphatic system and are particularly concentrated in the lymph

nodes. They produce special molecules called antibodies that have the ability to kill pathogens. Lymphocytes and antibodies are specific to the particular pathogen they target.

E.g. Cholera bacterium, for example, will trigger the body to produce specific cholera lymphocytes and antibodies that won’t work on any other pathogen.

B Lymphocytes: Produce plasma cells, which produce antibodies T Lymphocytes: Produce substances that attract pathogens. Others secretes substances that attract or activate phagocytes.

Others assist the b lymphocytes in production of antibodies. Memory Lymphocytes: Special lymphocytes that even after the infection are gone remain in our body for many years. IF we are invaded by the same pathogen again, the memory lymphocytes recognise it and are able to mount a much more

rapid immune response against it.Antibodies:

A protein Make antigens clumped together so it can be easily engulfed by the phagocytes Only works against one particular part of antigen.

Antigens: Foreign particle that stimulates on immune response – including parts of bacteria, viruses and other pathogens

Immune System: Immunity:

Some pathogens are able to successfully negotiate both the first and second line of defence. They are faced with a third response, an immune response involving a special type of white blood cells called lymphocytes.

Vaccinations:

It is a way of tricking the immune system into acting as though it has met a pathogen before, even if it has not. Edward Jenner took the first step towards developing a vaccine for smallpox when he noticed that milkmaids very rarely

contracted small pox. They are made of dead or weaker version of that pathogen.

Parasite:

A small animal that lives on or inside another body, which is the host, and uses the host for nutrients but does not kill it.

Bacteria:

One –celled organisms Carry out all the life functions They do not have a definite nucleus They have a cell wall. They do not have a chlorophyll They cannot make their own food.

Viruses:

Has no cell parts Does not ingest or digest food It does not carry respiration. Does not carry out any life function except reproduction and then only when it is living inside a another cell.

Australian Scientist:

Howard Florey:

Developed penicillin. Creating the first antibiotic

Society Influences:

Mental illness, bird flu, cancer, HIV/AIDs, swine flu etc. Major medical/health events affecting humans nationally, worldwide etc.

They can’t move by themselves, and carried by air or moving water. Some can move by themselves. Can be round, spiral or rod shaped Round : Coccus

Rod: Bacillus Spiral: Spirillum

Dynamic EarthEarth: A dynamic planet. The earth is active, rather than dead. The major systems or ‘spheres’ of the earth all interact with each other to constantly bring about changes and to recycle material through Earth.

The 4 major systems of the Earth are:

Atmosphere: This is the gaseous part of Earth, and extends approximately 200 km above the solid surface of the Earth. It is composed with gases like nitrogen, oxygen, argon, water vapour, carbon dioxide and a multitude of other gases.

Hydrosphere: This is the liquid part of Earth, and is composed entirely of liquid water, but also containing small amounts of dissolved materials, the most abundant of which is sodium chloride. It includes all the oceans as well as surface water on continents in rivers, lakes and wetlands; water frozen as ice in icecaps and groundwater.

Lithosphere: This is the solid, rocky part of Earth that extends from the surface down to about 100km or so

Biosphere: This is the region of Earth where life exists. The biosphere is the region where the interactions between the other spheres have produced conditions where life is possible.

Energy Source:

Earth’s dynamic systems have two sources of energy, one internal and one external.

Earths external energy source: Is the sun. Heat energy from the sun gives us our weather and climates, and also drives the major circulation currents in the oceans. The solar energy is the basis of nearly all living communities on the Earth’s surface.

Earth’s internal energy source: Is the radioactive decay of unstable isotopes in the deeper regions of earth – the mantle and the core. This radioactive decay produces heat, which drives the motions of the lithosphere – the movement of plates, which result in earthquakes and volcanic eruptions. This internal heat = energy basis for some kinds of living communities that live deep in the oceans and within rocks.

Natural Events:

Major events that originate in any of the Earth’s spheres are called natural disasters. These are disasters such as earthquakes, volcanic eruptions, cyclones, tsunamis, droughts and floods, have impacts on all spheres of the Earth.

Impacts of natural disasters on Earth’s different systems:

Event Cyclone Landslide Flood Volcanic Eruption

Disease Epidemic

System of Origin

Atmosphere Lithosphere Hydrosphere Lithosphere Biosphere

Effect on Atmosphere

High speed winds

Transfer of water

Heavy Rains

Pollution – Dirty and dusty air

Minor temperature

Amount of water in air

Minor

Toxic gases revealed into air

CO2 adds to the greenhouse effects

Solid particles Acid rain Cools earth

Particles and germs released into air

Minor pathogens passed by airborne diseases

Effect on Lithosphere

Faster Erosion

Erosion Change of

Increased erosion

Change of Landforms

Minor

Change of landforms

Landslides

landforms Deposition Adds new rock

Effect on Biosphere

Death and destruction of animals and humans

Destroyed houses

Death and destruction of trees; humans; animals; houses

Wipe out of humans

Pollution on the ground

Vegetation wiped out

Death Loss of

vegetation buried by ash or lava

Death of humans

Sickness Wipe out of

living things Defect on

death of Humans

EpidemicEffect on

Hydrosphere Floods Storm tide Water

pollution Strong

currents Sediments in

river

Water pollution

Dirty water Blocked rivers

Water pollution

Increased sediments in rivers

Water pollution

Contaminated Acidic toxic

dissolved in Tsunami Water

Can leave volcanic ash, blocking rivers and changing the river flow.

Contaminated water

Death of organism

Earthquakes:

What is an Earthquake? An earthquake is a shaking of the ground

How does an earthquake occur?

An earthquake occurs when the stresses caused by plate movements are released when the rock that make up Earth’s lithosphere break and move.

Most earthquakes occur on plate edges, especially where a plate is forced under another, e.g. Indonesia

Where do earthquakes occur?

Earthquakes are most common at plate boundaries, where different tectonic plates meet. The largest events usually happen where two plates are colliding – this is where large amounts of stress can

build up rapidly About 80% of all recorded earthquakes occur at the circum-Pacific seismic belt, commonly known as the

Rim of Fire due to the prevalence of seismic and volcanic activity.

Intraplate earthquakes:

Are earthquakes that occur within plates, well away from plate boundaries. These earthquakes occur less commonly and do not follow recognisable patterns Originate on more shallow levels

Tectonic Plates:

Earth’s outer surface is broken into pieces called tectonic plates These plates move constantly away from, towards or past each other, causing tension, compression or

shearing forces. Continents are part of these plates causing them to also move.

Epicentre:

Epicentre is the point or area on Earth’s surface directly above the source of Earthquake or focus.

Focus:

The focus of Earthquake is the source – the place inside earth where earthquakes originated. The point or zone inside earth where earthquake occurred and the energy was released

Focal Depth:

The depth to the focus Shallow Focus: < 30 km deep –most common Intermediate focus: Between 30 and 300 km deep Deep focus: Between 300 and 700 km deep –least common

Stress:

When an earthquake occurs, the rocks at the focus fracture and move, causing faults to form. The type of fault that forms depends on the type of stress.

Compression stress: Results in reverse faults, where rocks on one side are pushed up and over the other side

Tension stress: Results in normal faults, where rocks on one side slip down and apart from the other side Shearing stress: Results in strike-slip faults, where rocks on one side move horizontally past the other

side.

- Once a fault has formed, it acts as a line of weakness along which more earthquakes are most likely to occur.

Faults:

Faults are structures formed when rocks fracture and move during earthquakes. There are different types of faults depending on the type of stress and movement.

Normal faults: Are the result of tension forces pulling rock masses apart. One side of the fault moves down and apart from the other side

Reverse faults: Are due to compression forces, causing one side of the rock mass to move up and over the other side

Strike Slip faults: Are due to horizontal shearing forces. Rocks on one side of the fault move horizontally in the opposite direction to the other side. This can result in lateral displacement of surface features such as river beds, roads, fence lines and so on.

Earthquakes can cause tsunamis and landslides.

Seismic waves:

When an earthquake happens the energy released travels outwards from the focus in all directions. Like all energy it travels as waves – this is called seismic waves

How are earthquakes detected?

A seismograph records the vibrations caused by earthquakes and produces a seismogram An earthquake’s epicentre can be located accurately is three or more seismograms detect the event The latitude, longitude, depth and timing are needed to uniquely define an earthquake. The arrival of seismic waves depends on the type of vibration being carried

How are earthquakes recorded?

Seismograph: An instrument that records and detects seismic waves. Records and detects earthquakes. Usually made up of a frame firmly anchored to the ground from which a heavy mass is suspended by systems of hinges and springs, in such a way that it can oscillate (move back and forward) in one direction – up/down; side to side; backward/forward.

Seismogram: The recording made by a seismograph. A recording of an earthquake. Can be a trace made by a stylus or pen on paper of a revolving drum.

Seismic Energy:

Is transmitted away from the focus of an earthquake as seismic waves

Measuring Earthquakes:

Earthquake sizes are compared by measuring the maximum heights of the seismic waves at a distance of 100km from the epicentre

Richter Scale:

The Richter scale divides the size of earthquakes into categories called magnitudes. It measures the height and sizes of an earthquake

Modified Mercalli Scale:

Measures the intensity, and the effects of an earthquake.

Magnitude:

Describes the amount of energy released in an earthquake. The amount of energy released in an earthquake, measured on the Richter Scale Magnitude is measured on the Richter scale, which is an open ended, logarithmic scale (in other words it

goes up by powers of 10. In fact, each whole number increase corresponds to about a 30 times increase in energy)

Intensity:

Describes the effects of earthquakes at particular locations. A measure of the effects of an earthquake, measured on the MMs The effects of an earthquake on the natural and built environment

Waves:

Primary waves: - (p waves) arrive first and deform rocks by changing their volume, through a process which rapidly expands and compresses them. Therefore P waves are compression waves. They can travel through all mediums.- compression waves (identical to sound waves); have the highest velocity (6-13km/s); travel through earth; can travel through all mediums – solid, liquid and gas.

Secondary waves: - (s waves) arrive next and deform rocks by changing their shape, or shearing them. Therefore s waves are transverse waves. They can only travel through solids. - Transverse waves or shear waves; slower than p waves (3-6 km/s); travel through earth; can only travel through solids

Surface waves: - ( L waves) arrive last and pass around the surface of Earth rather than through it.- The slowest waves; travel around the surface of earth; make the ground shake.

Tsunamis:

What is a tsunami?

Tsunami’s are waves which can cross oceans and which may cause extensive damage in coastal regions It is a Japanese word; ‘tsu’ meaning harbour and ‘nami’ meaning wave. Are very fast ocean waves, cause by a disturbance of the ocean floor.

How do tsunamis occur?

Tsunamis are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land lumping into the ocean, major volcanic eruptions or large meteorite impacts.

Most tsunami’s are caused by large earthquakes at the sea floor, when large slabs of rocks are forced to move up or down relative to each other suddenly causing the overlying water to move.

Underwater landslides and less common are tsunamis initiated by volcanic eruptions. These can occur in several ways;- if an underwater volcano erupts, the hot lava may heat the surrounding water quickly and explosively.- massive flows of volcanic debris such as ash can travel down the side of a volcano and into the ocean, pushing water outwards.- the top of an underwater volcano may collapse downwards, so that the overlying water also drops.

Large meteorite impacts that occur at sea can trigger tsunamis too.

Tsunamis differ from normal ocean waves because in a tsunami the total depth of ocean water moves.

When they approach shallow water, they slow down and the wave height builds up.

Earthquake Boundaries:

Boundaries:

Earthquakes occur at the boundaries between earth’s lithospheric plates. This is where huge stresses build up in rocks as plates try to move apart from each other, grind past each

other or one plate tries to push under and adjacent plate. Eventually these stresses get too great and the rocks fracture and move suddenly releasing the strain

energy.

Lithospheric plates:

Plates are fragments of Earth’s rigid outer shell, which is called the lithosphere. The lithosphere is about 100 km thick, and is made up of the crust and the rigid top section of the mantle. Therefore each plate is a 100km thick slab of rigid work, like a piece of broken egg shell

Asthenosphere:

The region where the rock is ‘soft’ or mobile, and able to flow It flows slowly by convection

What makes the plates move?

Convection currents allow the plates to move In the atmosphere the convection currents are thought to drag the lithosphere along on the top of it.

How do we know where the boundaries between plates are?

Where the earthquakes occur in the narrow linear zones or bands around the earth By seeing where most of the earthquakes occur

What are plates composed of?

The lithosphere; the rigid rock that make up the outer ‘shell’ of the earth Slabs and rigid rocks

In what way is the asthenosphere different from the lithosphere?

It is hotter than the lithosphere It is the region where the rock is ‘soft’ or more mobile and able to flow;(lava) while the lithosphere is solid

and not able to flow; (rock)

Crust:

Earth’s crust is simply the outermost part of the lithosphere There are 2 different types of crust:

- Oceanic crust – Ocean is made out of- Continental crust – Continents are made out of

Plates and Continental Motion:

As the plates move, the crust on their surface gets carried along with it The continents are simply masses of low density continental crust being carried along passively on the

surface of moving lithospheric plates

Plate boundaries and geologic activity:

Most geologic activity occurs at the boundaries between plates Geologic activity includes earthquakes, volcanic eruptions and mountain building

Divergent Boundaries:

Adjacent plates move apart from each other

Convergent boundaries:

Adjacent plates push towards each other

Conservative Boundaries:

Adjacent plates slide past each other

Divergent Boundaries:

MOR – Mid Ocean Ridge:

- The name given to the great undersea mountain range that is present in all oceans Running through all the major oceans on Earth is a huge undersea mountain range called a MID-OCEAN

RANGE (MOR). The mid ocean range system is the largest landform feature on earth MOR’s rise about 3000 m above the ocean floor and are 2000 – 3000km across the base MOR’s are places where shallow focus earthquakes occur. They have a central rift valley running along the crest; this rift is bounded by normal faults Volcanic activity also takes place, erupting very fluid (runny) basalt lava In most places MORs are below sea level In a few places, such as Iceland, the MOR is above sea level

Main features of MORs:

Have a central rift valley running along the crest About 3000m high above deep ocean focus Mainly below sea level except for Iceland Places where shallow focuses, earthquakes occur

Pillow Lava

This is the lava formed under the ocean when erupted

Sea Floor Spreading:

Harry Hess proposed that MORs are places where the oceanic crust is pulling apart

Sea Floor Spreading Hypothesis:

In the mantle underneath MORs, rising convection currents bring rock up from the deep mantle It partly melts and produces magma, with the composition of basalt. The basalt magma rises into the fissure cracks in the centre of the MOR, most of it solidifying as dykes Some erupts at the surface to form flows of pillow lava As the lithosphere pulls apart further, new fissures open up, to be filled with fresh magma.

As a result of the tension (pulling apart) forces, structures, such as normal faults are produced

Explain how the process of sea floor spreading works:

The ocean crust pulls apart in that opens up vertical cracks along the crusts of the mid ocean range. Magma from the mantle rises into the cracks forming new rocks. Pulling apart forces continues to create and open new cracks.

- Rocks are brought up by rising convection currents- Then they partly melt and form magma.- This magma solidify in the crack of the MOR as the lithosphere pulls the MOR apart- New magma rises and fills the cracks.

Confirming Sea Floor Spreading:

If the sea-floor spreading hypothesis is correct then ;- The basalt ocean crust should get older further away from the MOR- The ocean floor sediment should get thicker, further away from the MOR

Rates of sea-floor spreading:

Rate = DISTANCE (KM) ÷ AGE (MILLION YEARS) = ________ km/Ma(convert to units of cm/ year by dividing it by 10) = ________ cm/y

Conservative Boundaries:

Conservative boundaries are locations where plates move past each other These boundaries are characterised by

- Frequent and often intense shallow focus earthquakes- No volcanic activity- Prominent strike-slip faults- Linear mountains or depressions

Examples : San Andreas Fault (California); Alpine Fault ( NZ)

Conservative boundaries : Plates my slide past one another!

Convergent Boundaries:

In other parts of the ocean floor, particularly around the margins of oceans, are deep ocean trenches. These ocean trenches are always next to, and on the ocean side, of large mountain ranges on continents, or

next to chains of volcanic islands These plates are where plates push together. These locations are convergent plate boundaries. One plate gets pushed or dragged down under the other in a process called subduction

Convergent boundaries are characterised by:

Deep ocean trench on the ocean side of the boundary Intense earthquake activity. Earthquakes get progressively deeper further under the overriding plate. This

zone of descending earthquakes is called a Benioff Zone. Explosive, often violent volcanic activity, producing very viscous lava and abundant pyroclastic material

(volcanic ash) Mountain ranges made up of rocks that have been folded and thrust faulted. These mountain ranges are

called Fold Mountains.

Convergent Boundaries:

Ocean-Ocean Convergence:

Both plates have oceanic crust Examples: Vanuatu, Tongan Islands, Kuril Islands

Ocean-Continent Convergence

A plate carrying oceanic crust may collide with one carrying continental crust. One plate has continental crust, the other oceanic crust Examples: West coast of South America

- Volcanic activity is caused by magma which is produced when the subducting plate begins to melt.- The magma is hot and therefore less dense than the solid rocks around it, so the magma rises, melting

its way through the overlying plates.- This magma tends to be quite viscous (thick and stiff) and contains a lot of dissolved gases, mostly

water vapour- This makes a dangerous combination because when this magma reaches the surface, the dissolved

gases cannot easily bubble out.- The gas pressure builds up until the lava explodes violently, causing highly dangerous eruptions of

volcanic ash and dense clouds of hot gases mixed with volcanic ash.

( Pyroclastic flows = dense clouds of hot gases mixed with volcanic ash)

- The subducting plate is dragged back down into the deeper mantle; it rubs against the overriding plate, and also breaks up as it descends.

- Both these things cause earthquakes, in a pattern getting deeper further away from the trench.- Benioff Zone : The descending zone of earthquakes

Continent-Continent Convergence:

Both plates have continental crust Plates carrying continental crust may collide with one another Example: Himalaya Mountains

Harry Hess & Alfred Wegener:

Alfred Wegener proposed the theory of Continental Drifts in 1910’s Harry Hess proposed the theory of sea-floor spreading, in the 1960’s, also the subduction hypothesis

The Facts Of Life:Define the term Sexual Reproduction:

Sexual reproduction is the fusion of the male and the female reproductive cell (gamete) and results in offspring to help insure the survival of the species.

The cells of the offspring have two sets of chromosomes (one from each parent), so are a genetic mix of their parents.

Male Gametes- Sperm:

Sperm are reproduced in the testes Testosterone is a male hormone that is needed to produce sperm. Sperm make up less than 1% of the semen but there are about 400 million sperm in each ejaculation.

Female Gamete: Ova

Eggs are produced in the ovaries. The Hormones FSH, (Follicle stimulating hormone), LH (Luteinising hormone), oestrogen and progesterone

are needed to mature the egg. Only one egg/ month is released and there are about 400,000 in the ovaries. Only About 400 ever mature.

Compare and contrast internal and external fertilization.

Internal Fertilization:

Egg and sperm stay inside the body Sperm are introduced to the egg by copulation (mating) Mainly land animals Most ZYGOTES develop internally.

Advantages:

Developing Embryo/ foetus is protected from predators and environment.

Disadvantages:

Limited number of offspring at once and longer gestation.

Examples:

Humans Dogs Cats

External Fertilization:

Mainly Aquatic animals.

Rabbits Elephants.

Eggs and sperm released outside the body into water (to stop them from drying out). Sperm fertilize the egg in the water and they develop outside the body.

Advantages:

Many offspring can be produced at one time.

Examples:

Fish Sharks

Draw a flowchart of the process of fertilisation:

Label the male and female reproductive organs:

Identify the organs that produce gametes:

Female- Ovaries:

o Ova (female’s sex cells) are made in the Ovaries.

Disadvantages:

Predators can eat the Zygotes.

Zygotes may die in the environment and not survive.

Starfish Coral

Male- Testes:

o Sperm is made in the testes of a male when he is sexually mature.

Describe the difference between ovulation and menstruation:

Ovulation- The mid-point in the menstrual cycle when a mature ovum is released from an ovary.

Menstruation: Monthly bleeding, sometimes called ‘periods’. It occurs as the lining of the uterus is released.

Discuss the roles of the hormones, oestrogen and progesterone

Hormones: Chemical substances produced by glands and circulated in the blood. Hormones have specific effects in the body:

o The female reproductive cycle is completely run by hormones. Without the hormones, conception would not occur.

o There involved in many actions in our body such as: blood pressure, heart rate, reproductive issues, sugar blood levels

Oestrogen: A female sex hormone produced in the ovaries.

o Estrogen is the hormone responsible for the low basal body temperatures in the first half of the cycle. Estrogen prompts the cervix to produce the fertile quality cervical fluid. It controls the entire menstrual cycle.

Progesterone: A female sex hormone that helps prepare the uterus lining for a pregnancy and is responsible for its shedding if implantation of an embryo does not occur.

o Progesterone is produced by the corpus luteum after ovulation has occurred.o Progesterone is responsible for the higher basal body temperatures. It helps to build and maintain the

uterine lining for the fertilized egg and helps to keep the lining should pregnancy occur. Progesterone is also responsible for the drying up of the cervical fluid and for the change in cervical position during the second half of the reproductive cycle.

Describe the development of the embryo into a foetus:

As the fertilized egg develops into the baby we see at birth, it goes through three main stages of growth: 1. the stage of the zygote (before implantation), 2. the stage of the embryo (early in the pregnancy), and 3. the stage of the fetus (later in the pregnancy).

During the first month of its life, the human embryo looks like that of any other higher animal, such as a cat, dog, or pig, for example. During the second month, it slowly assumes human features. It starts to develop a recognizable face, as well as arms, legs, fingers, and toes. Between its legs, the primitive beginnings of sexual organs become discernible, although they are still undifferentiated at this point (i.e., they are the same for both male and female). When the entire growing organism finally becomes clearly identifiable as human, it leaves the stage of the embryo and enters that of the fetus.

Outline some of the reasons for infertility:

Infertility is when a couple has been trying to have a baby for at least a year and for some reason they cannot conceive. When this happens it is classified as infertility.

For most men the infertility causes is the result of having a low sperm count. The lifestyle that a man chooses can affect his sperm count as well. For instance, if a man smokes cigarettes, they will have a lower sperm count than a man that doesn’t.

Ovulation is one of the main factors that infertility causes in women. Several factors cause a decrease in ovulation such as being in stressful situations.

Women- the age factor, as years passes by, each year’s potential of producing quantity of eggs is lowered

and that leads to woman infertility, as woman enters in their thirties the possibilities of getting pregnant

start to decrease and after mid thirty, it decreases with speed.

PID or blocked fallopian tubes which stops the egg going through womb it could be because of any reasons

such as endometriosis or inflammatory disease of pelvic that is infection.

Identify and describe the process of In- Vitro Fertilization:

IVF: In vitro fertilization, a laboratory procedure in which sperm are placed with an unfertilized egg in a Petri dish to achieve fertilization. The embryo is then transferred into the uterus to begin a pregnancy or cryopreserved (frozen) for future use.

Outline some of the issues involved with reproductive technology:

Reproductive technology encompasses a range of techniques used to overcome infertility, increase fertility, influence or choose the genetic characteristics of offspring, or alter the characteristics of a population. Each type of reproductive technology brings with it a range of ethical issues. With the accelerated pace of progress in modern medical technology, these issues have been brought squarely into the public arena, where they continue to provoke controversies involving the boundaries of government control, private choice, religious belief, and parental wishes.

Identify the relationship between atoms, molecules, organelles, cells, tissues, organs and systems:

It’s the order of life : Atoms (has protons and neutrons) make molecules, molecules make organelles and are

the small organs in each cell (nucleus, ribosome etc) , cells (building blocks of life) are made up of organelles,

tissues are made from similar cells (each organ has specific types of cells that make that particular organ and

its parts), organs are made from similar types of tissues, organ systems are organs that work together to

help an organism execute a specific function (breathing)

Atom is the smallest indivisible particle of matter that can have an independent existence.

Molecule is Units of two or more atoms held together by chemical bonds.

Organelle is A subunit of a cell, it is involved in a specific subcellular function.

Cell is The fundamental unit of living things.

Tissue is a group of cells performing a specific function.

Organ is a group of cells or tissues performing an overall function.Identify and describe the role of the nervous system:

The nervous system helps all the parts of the body to communicate with each other. It also reacts to changes both outside and inside the body. The nervous system uses both electrical and chemical means to send and receive messages.

The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body

Describe the pathway of a reflex arc:

A reflex arc is the neural pathway that mediates a reflex action. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This characteristic allows reflex actions to

occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs.

A reflex arc refers to the neural pathway that a nerve impulse follows. The reflex arc typically consists of five components

The receptor at the end of a sensory neuron reacts to a stimulus. The sensory (afferent) neuron conducts nerve impulses along an afferent pathway towards the central

nervous system (CNS). The integration center consists of one or more synapses in the CNS. A motor (efferent) neuron conducts a nerve impulse along an efferent pathway from the integration center

to an effector. An effector responds to the efferent impulses by contracting (if the effector is a muscle fiber) or secreting a

product (if the effector is a gland).

Define Receptor, Effector and Neurotransmitter:

Receptor: Specialized cell or group of nerve endings that responds to sensory stimuli.

Effector: Muscle, gland, or organ capable of responding to a stimulus, especially a nerve impulse.

Neurotransmitter: A chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. A neurotransmitter is a messenger of neurologic information from one cell to another.

Identify and describe the role of the cerebrum, cellebrum and brainstem:

Cerebrum: The cerebrum is largely responsible for interpreting your sensations (sight, hearing, touch, etc) and moving your muscles. It also is the seat of consciousness and where your personality arises from.

Cellebrum: The cerebellum is a region of the brain that plays an important role in motor control. It is also involved in some cognitive functions such as attention and language, and probably in some emotional functions such as regulating fear and pleasure responses but it is its function in movement that is most clearly understood. It does not initiate movement, but contributes to coordination, precision, and accurate timing. It receives input from sensory systems and from other parts of the brain and spinal cord, and integrates these inputs to fine tune motor activity. Damage to the cerebellum produces disorders in fine movement, equilibrium, posture, and motor learning.

Brainstem: The brainstem is the posterior part of the brain, adjoining and structurally continuous with the spinal cord. The brain stem provides the main motor and sensory innervations to the face and neck via the cranial nerves. Extremely important part of the brain as the nerve connections of the motor and sensory systems from the main part of the brain to the rest of the body pass through the brain stem. The brain stem also plays an important role in the regulation of cardiac and respiratory function. It also regulates the central nervous system, and is pivotal in maintaining consciousness and regulating the sleep cycle.

The brain stem plays a vital role in basic attention, arousal, and consciousness. All information to and from our body passes through the brain stem on the way to or from the brain. Like the frontal and temporal lobes, the brain stem is located in an area near bony protrusions making it vulnerable to damage during trauma.

Describe the role of the endocrine system:

The endocrine system, it influences almost every cell, organ, and function of our bodies. The endocrine

system is instrumental in regulating mood, growth and development, tissue function, metabolism, and

sexual function and reproductive processes.

In general, the endocrine system is in charge of body processes that happen slowly, such as cell growth.

Faster processes like breathing and body movement are controlled by the nervous system. But even though

the nervous system and endocrine system are separate systems, they often work together to help the body

function properly

Explain what a hormone is and where it is made:

o A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism.

As members of the endocrine system, glands manufacture hormones. Hormones circulate freely in the bloodstream, waiting to be recognized by a target cell, their intended destination. The target cell has a receptor that can only be activated by a specific type of hormone.

Hormones are secreted (usually into the bloodstream) by a collection of glands inside the body referred to as the "endocrine system." (A "gland" is a group of cells that produces and secretes chemicals into the body.) The major glands that make up the endocrine system include the hypothalamus, the pituitary gland, the thyroid and parathyroids, the adrenals, the pineal body, and the ovaries and testes (the "gonads").

Describe at least one scenario where hormones are used in the body:

The female reproductive cycle is completely run by hormones. Without the hormones, conception would not occur.

There involved in many actions in our body such as: blood pressure, heart rate, reproductive issues, sugar blood levels.

Discuss the benefits and ethical issues associated with technology (e.g stem cells) in treatment of people with nerve disorders or injuries.

The stem cell controversy is the ethical debate centered only on research involving the creation, usage, and destruction of human embryos. Most commonly, this controversy focuses on embryonic stem cells. Not all stem cell research involves the creation, usage and destruction of human embryos. For example, adult stem cells or induced plenipotent stem cells, which do not involve creating, using or destroying human embryos, is not as highly controversial.

Mysterious Universe:

Waves:

A wave is able to transmit energy from one place to another without moving any matter over the same distance

Transmitter of energy without the movement of particles from place to place. The vibration of particles or energy fields is involved.

Energy: The capacity of a body or system to do work. A supply or source of electrical, mechanical, or other form of powerWave: Transmitter of energy without the movement of particles from place to place. The vibration of particles or energy fields is involvedMedium: Material through which a wave moves

Amplitude: Maximum distance that a particle moves away from its undisturbed position. Half height of the wave, bigger the amplitude the more energy it has. Frequency: A number of vibrations each secondSpeed: The rate of movement at which something moves, happens or functions. Wavelength: Distance between two neighbouring crests or troughs of a wave. This is the distance between two particles vibrating in step. Distance between two consecutive points on a wave

Mechanical and Electromagnetic Waves:

Electromagnetic:

Electromagnetic energy that is transmitted as moving electric and magnetic fields. There are many different types of electromagnetic energy e.g. light, microwaves, radio waves No medium is required These are transverse waves Are caused due to the change in electric and magnetic fields

Mechanical:

Medium is required These are longitudinal waves or transverse waves Produced due to the vibrations of the particles of the medium Just vibrate to and fro about their mean position.

- Sound Waves: Compression wave. Caused by vibrations, which causes air to compress- Water Waves

Transverse & Longitudinal Waves:

Transverse:

Wave involving the vibration particles perpendicular to the direction of energy transfer Each part of the wave moves at right angles ( 900 ) to the direction the energy is moving in. Displacement is at right angles to the direction of the wave Means across

Longitudinal:

Also known as Compression waves Moving particles move backwards and forwards in the same direction as the energy transfer. Wave involving the vibration of particles in the same direction as energy transfer

Law of Reflection:

When light strikes a shiny surface like a mirror, the angle of incidence equals the angle of reflection

The law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror all lie in the same plane. Furthermore, the angle of reflection is equal to the angle of incidence . Both angles are measured with respect to the normal to the mirror.

Reflection:

When light strikes a shiny surface like a mirror, light is reflected from surface.

Refraction, Dispersion, Scattering:

Refraction: Change in the speed of light as it passes from one substance into another. It usually involves a change in direction

- Bending of light through different media

- When light speeds up as it does when it passes from water into air, it bends away from the normal

- When light slows down, as it does when it passes from air into water, it bends towards the normal

Dispersion: separation of the colours that make up white light. Each colour is bent differently when it enters or leaves a glass prism

- Happens because each colour of light has a slightly different speed in glass and is, therefore, refracted at a slightly different angle

Scattering: Describes light sent in many directions by small particles within a substance.

- Individual rays of light cannot be seen but streams of light rays or beams of light may be seen when the light is scattered or reflected from particles in substances and then redirected to the eye.

- Beams of light can often be seen from car headlights on a foggy night as light is scattered from water vapour in the air

Electromagnetic – Reflected, refracted and scattered:

Reflection is the change in direction of a wave due to its bouncing off a boundary between two media. This effect is used by shortwave AM radio frequencies. Signals are deliberately bounced off the ionosphere.

Scattering occurs when shorter wavelengths strike an object and are reflected in many directions, e.g. microwaves can be scattered by rain. Scattering weakens the signal.

Refraction is the change in direction of a wave when it moves into a new medium. This causes a change in the wave velocity.

Electromagnetic radiation moves as a wave, but can demonstrate particulate properties. Because of this physical phenomenon, its movement is expressed as having wave-particle duality. Whilst moving through space, the direction and speed of radiation can be altered by being reflected, refracted, scattered, or absorbed.

Reflection of radiation occurs when the frequency of the incident ray doesn’t match the natural frequency of the atoms electrons. The electrons absorb the energy, but instead of vibrating continuously with a large amplitude, they quickly return to their previous state, and the energy is reemitted (reflected ray).

Universe:

It is difficult to get information about the universe as scientists have been only able to calculate how much stuff is there in the universe.

Concluded that we know so little, and only know some features inside our universe like stars, planets and black holes.

They also know how these objects form and interact

Big Bang Theory:

The universe began about 13.7 million years ago with a ‘big bang’ First suggested because due to Einstein’s theory on gravity, the universe had to be expanding. Found out red

shift was caused by the expansion of the universe, galaxies continuously moved away from the solar system, each other, at high speed.

Evidence for the big bang began to emerge as new technological advances were made. The biggest advances came with the development of increasingly sensitive scientific instruments and the

launch of the earliest satellites equipped with sensors that could relay information about space from beyond the limits of our atmosphere. - The Red Shift:

o Provided evidence for expanding universeo A steady state universe could only expand if new galaxies and stars replaced those that moved

away. There is no way to explain how these stars and galaxies were created from nothing. Have not been found

- The Elements:o Amount of hydrogen and helium in the universe supported the big bang theoryo Steady State: The only way that helium can be produced is by the nuclear reactions taking place

in stars.o About 8.7% of the atoms in the universe are helium – far more than could be produced by the

stars aloneo Percentage of helium atoms can however be explained by their creation as a result of the big

bang - The Afterglow:

o Universe would now be 13.7 billion years after creation, having a temperature of 2.7 degrees above absolute zero, that is -2700C

o Gamow predicted that because of its temp universe would be emitting an afterglow of radiation ‘cosmic microwave’

o Radiation discovered by accident – 1965o Picked up consistent radio noise that they couldn’t’ get rid ofo Noise wasn’t coming from anywhere on earth, because it was coming from all directionso It was the cosmic microwave background radiation predicted by Gamow.

Life Cycle of A Star:

Stars are born in a dense cloud of gas and dust found in the spiral arms of galaxies. The raw ingredients of a star are called a Nebula. The star actually forms when dense regions in these clouds collapse under their own gravity.

The nebula’s gas and dust come closer together forming a protostar. As more material is packed in the protostar, the centre gets hotter and hotter until conditions are suitable

for nuclear reactions to begin together to form helium. At this stage, a main sequence star, like our sun is formed.

Stars have limited amount of fuel (hydrogen) that eventually runs out Those like our sun will last around 10 billion years before it happens. Transformation takes places depending on how big the star is. A star with a mass of one sun will start to use

helium as a fuel, producing carbon in the process. It also begins burning hydrogen in the atmosphere and in doing so, expands bigger than original diameter to become a Red Giant

Without the pressure produced by nuclear reactions, the remaining centre collapses under its own gravity to form a small, very dense core called a White Dwarf

A star with a mass 10 x that of the sun uses up its fuel supply much more rapidly over a period of about 30 million years and becomes a blue supergiant, before further expanding to form a red supergiant.

Inner core collapses in less than a second, causing a large explosion called a supernova. This explosion blasts matter into space and shines for about a month with the intensity of billions of stars. It is a supernova that elements such as gold, silver and iron are formed.

The remains of the star form what is called a neutron star.

If a star is explosive enough, it collapses even more than a neutron star to form a black hole-an object so dense that anything close by will be drawn into it by its overpowering gravity. Gravity is so strong that even light cannot escape! They distort the space around them, and can often suck nearby matter into them, including other stars. As matter swirls into the black hole it becomes incredibly hot and emits tell-tale X rays.

Gravity:

Gravity: The force that makes any two objects that have mass move towards each other. The most common example of this is when an object falls to the ground

It acts between all objects in the universe Gravitational Force: the attraction due to gravitation that the Earth or another astronomical object exerts on

an object on or near its surface

Black Hole

Black holes are believed to form from massive stars at the end of their lifetimes. The gravitational pull in a black hole is so great that nothing can escape from it, not even light.

The density of matter in a black hole cannot be measured. Black holes distort the space around them, and can often suck neighbouring matter into them including stars A black hole is a super dense object that has an intense gravitational pull. An object so dense that anything close by will be drawn into it by its overpowering gravity. Gravity is so strong that even light cannot escape! They distort the space around them, and can often suck

nearby matter into them, including other stars. As matter swirls into the black hole it becomes incredibly hot and emits tell-tale X rays.

Chemicals All Around:Chemical Reaction:

Chemical reactions occur when the bonds between atoms are broken and new bonds are formed creating a new combination of atoms

In fact, once a new substance has been formed it is signalled by observable changes – a change in temperature– Change in colour– Formation of precipitate – Formation of a gas– Different smell

Bonds between the atoms of the reactants have been broken and new bonds formed. The same atoms are present in both the reactants and the products; that is, no new atoms have been

introduced during the reaction. The atoms that were present at the beginning of the reaction are still the same ones present at the end. The reaction has simply been a rearrangement of the atoms

Physical Change:

Substances are not altered chemically. No new products are formed Chemical bonds are not broken in a physical change It can affect the size, shape, colour of a substance but does not affect its composition. My change to another phase (i.e. gas, liquid, solid) or separated or combined. It can be reversible

Chemical Change:

Cannot be reversible. Irreversible Substances are altered chemically and display different physical and chemical properties after the change New substance (s) are formed through a reorganisation of the atoms

Compounds:

Atoms in a compound are not the same They are stuck together Whether it is a solid, liquid or gas atoms are chemically bonded in a way that new reactions are formed

Mixtures:

Contains different atoms mixed together They are not stuck together Solid, liquid or gas combined in a way, that they are not combined

Law of Conservation of Mass:

The law of conservation of mass states that matter can be neither created nor destroyed during a chemical reaction

Exothermic and Endothermic:

Exothermic:- Chemical reactions that give out heat energy to the surroundings

Endothermic:- Chemical reactions that absorb heat energy from the surroundings

Compounds and Formulas:

Compound FormulaWater H20 Citric Acid C6H8O7

Oxygen O2Carbon Dioxide CO2Hydrogen H2Hydrochloric Acid HClCarbon Monoxide COSodium hydroxide NaOHSodium Chloride NaClSodium Hydrogen Carbonate NaHCO3

Sodium Sulphate Na2SO4

Sodium citrate C6H5O7Na3

Magnesium chloride MgCl2

Mercury (III) Oxide HgOCopper Sulphate CuSO4

Copper hydroxide Cu(OH)2

Acids and Bases and Salts:

Acids:

- Sour in taste- End with Acid

Bases: - End usually with Hydroxide / oxide

Acetic Acid: Vinegar: CH3COOH : HC2H3O2

Hydrochloric Acid: Toilet cleaners, gastric juice: HCL Sulfuric Acid: Car Batteries, lead battery: H2SO4

Carbonic Acid: Fizz in Soft Drinks, club soda, soft drinks,: H2C03

Ascorbic Acid: Vitamin C: C6H8O6

Citric Acid: Fruit Juices: H3C6H8O6

Elements:

All atoms in an element are the same

- Bitter in taste and soapy touch Magnesium Hydroxide: Mg(OH)2

Aluminium Hydroxide: Al(OH)3

Salts: - Chloride , carbonate

Sodium Sulfate: Na2SO4

Sodium Hydrogen Carbonate: NaHCO3

pH:

Is a measure of the acidity or alkalinity/basicity of a solution A measure of the acidity or alkalinity of soil, water and so on, running from 1 (extreme acidity) to 14 (extreme

alkalinity)

pH Scale:

Scale from 1 (acidic) to 14 (basic) that measures how acidic or basic a substance is.

Indicators:

Indicators are substances that change colour in the presence of an acid or base. Can be used to determine whether a solution is acidic, neutral or basic. This is useful in the laboratory as well as

domestically. Detect whether the water in swimming pool is too acidic or basic. Can be used in neutralisation reactions to determine the point where exact neutralisation occurs.

Universal indicator:

Is a useful mixed indicator that shows a large range of colours over the pH scale. 0-4 – red

4-5 – Orange5-6 – Yellow7-8 – Green

Neutral – pH of 7 Acidic = pH less than 7. The lower the pH the more acidic is the solution Strongly Acidic – 0-2 Basic Solutions – more than 7. Higher the pH more basic is solution Strongly Basic – 12-14

Neutralisation/Base:

Acid + Base Salt + Water- Hydrochloric acid + Aluminium Hydroxide Aluminium chloride + Water- Hydrochloric acid + Magnesium Hydroxide Magnesium Chloride + Water

Metal:

Metal + Acid Salt + Hydrogen Gas

Carbonate:

Carbonate + Acid Salt + Carbon Dioxide + Water

Solute, Solvent, Solution:

Potassium Hydroxide: KOH Sodium Hydroxide: NaOH Ammonia: Gas : NH3

Calcium Chloride: CaCL2

Sodium Chloride: Table Salt: NaCL

8-9 – Blue-green9-10 – Blue- Violet10-14 – Violet

Solute: Substances that are dissolved in the solvent to form a solution

Solvent: Substances in which a solute dissolves to form a solution

Solution: Mixture of a solute dissolved in a solvent. Solutions are clear but can be coloured.

Precipitate & Precipitate Reactions:

Precipitate: The solid product of chemical reactions. Do not dissolve

Precipitate Reaction: Reactions when reactants are solutions and one of the products is a solid

Variables:

Independent: The variable that a scientist changes to observe its effect on another variable.

Dependant: Variable that is expected to change when the independent variable is changed. The dependant variable is observed or measured during the experiment

Genetics: Identify the needs of cells and the systems in the body that provide these:

The needs of cells:

To survive, each cell needs nutrients, water and oxygen gas As cell grows and develops chemical reaction of life which goes on inside, the cell makes use of these

substances Chemical reactions also produce waste like urea and the gas; carbon dioxide These wastes are toxic to cells and must be excreted Unicellular organisms (made up of one cell): Substances it needs can enter the cell easily from the

surrounding environment. Waste can be let out directly into the environment. Multicellular organism (made up of many cells): Not every cell is in direct contact with environment. This is

why they are divided into various systems, to make sure cell needs are met. Each specialised body system performs a specific role. The systems work together to ensure the body

functions properly as a whole.

Body systems and their functions:

Digestive: Breaks down food into a form which can be absorbed by cells.

Nervous: Controls and coordinates bodily activities and functions

Circulatory: Transports nutrients, oxygen and water to cells and wastes away from cells

Excretory: Filters waste like urea from blood stream

Endocrine: Produces hormones which controls many body functions

Immune: Helps protect body against disease by destroying bacteria and other micro-organisms by producing anti bodies

Respiratory: Gets oxygen from air, removes carbon dioxide and excess water from body

Reproductive: Produces gametes which are needed for production of new life

The Connection Between DNA & Chromosomes:

Chromosomes: tightly coiled strands of DNA and protein arranged in a specific structure. They are found in the nucleus of all living cells.

DNA: molecules that are encoded with info to make all living things Genes: Are words in a DNA sentence. Contain codes for a particular characteristic.

What is DNA?

In a DNA, instructions providing all of the information necessary for a living organism to grow and live reside in the nucleus of every cell.

These instructions tell the cell what tole it will play in the body. Chromosomes DNA Strands DNA Helix

DNA HELIX - The instructions come in the form of a molecule called DNA. DNA encodes a detailed set of plans, for example – a blueprint, for building different parts of the cell.

What is a Chromosome?

Each cell in our body contains a lot of DNA. All our DNA is packaged into compact units called ‘chromosomes’.

The packaging of DNA into a chromosome is done in several steps, starting with the double helix of DNA. The DNA is then wrapped around some proteins.

The proteins are packed tightly together until they form a chromosome. Chromosomes are efficient storage units for DNA.

Structure of DNA:

DNA is a chemical molecule made up of repeating units called NUCLEOTIDES

A single nucleotide is made up of a phosphate molecule, a sugar molecule, and a nitrogenous base. Nitrogenous base: Either Adenine, Thymine, Cytosine or Guanine

DNA Helix:

The DNA molecule comes in the form of a twisted ladder shape scientist call a “double helix” The sugar and phosphate bases make up the side of the ladder and the nitrogenous base pairs make up the

steps of the ladder. The ladder’s rungs are built with the four-letter DNA alphabet: A, C, T and G. The alphabet pieces join together according to special rules.

Describe the benefits and limitations of using a physical model of DNA:

Benefits:

You can physically see the structure of a DNA Able to see which base fit together Gives you a better understanding of what makes up a DNA

Limitations:

Not to scale – not accurate Very small representations

A + T & C + G (A always with T, C Always with G)

A – Adenine T – Thymine C – Cytosine G – Guanine

Very general and simple It’s not looking at it at an atomic level

Describe the connection between DNA, Genes & Proteins:

DNA is made up of genes which are the information to make protein which make up the parts and chemicals in our body

Describe the role of proteins in the body:

They are required for the structure, function and regulation of the body’s tissues and organs Proteins are very important molecules in our cells. They are involved in virtually all cell functions. Each protein within the body has a specific role. Some proteins are involved in structural support, while

others are involved in bodily movement, or in defence against germs. Proteins vary in structure as well as function. They are constructed from a set of 20 amino acids and have

distinct three-dimensional shapes. Below is a list of a few types of proteins and their functions:- Antibodies defend the body from germs.- Contractile proteins are responsible for movement.- Enzymes speed up chemical reactions.- Storage proteins store amino acids.

Scientists involved in the discovery of the structure of DNA and their role in the discovery:

Rosalind Franklin:

Discovered that the sugar-phosphate backbone of DNA lies on the outside not the inside She discovered that the DNA structure wasn’t a 3 strand helix but a 2 strand helix

Maurice Wilkins:

Had the idea to study DNA by X-Ray crystallographic technologies

James Watson and Francis Crick:

Made the 3D version of a double helical DNA molecule out of cardboard cut outs. The method of X-ray which Watson and Crick used to determine the double helical structure of DNA was one which Rosalind Franklin had developed and was using for a different purpose.

Walter Sutton:

Theory that the Mendelian laws of inheritance could be applied to chromosomes at the cellular level of living organisms..

Alfred Sturtevant:

Constructed the first genetic map of a chromosome.

Basic Stages of Mitosis:

Mitosis – needed for body cell division It results in 2 identical daughter cells It occurs within all body cells and is needed for growth and

repair Body cells contain 2 sets of chromosomes. These cells are

called diploid (2n) n= number of chromosomes 46 chromosomes = Diploid i.e (2N) 1st Step of mitosis involves DNA in the parent cells replicating itself

- The cell has to double its DNA first so that when the parent cell divides, the daughter cells can have the right number of chromosomes.

In mitosis:- No variation arises from offspring- All genetically identical ( except it there is mutation)- It occurs in bacteria, plants which produce asexually

Differences:

o Mitosis The process of cell division which results in the production of two daughter cells from a single parent

cell. The daughter cells are identical to one another and to the original parent cell. Produces two identical daughter cells during Interphase, prophase, metaphase, anaphase, and telophase

o Meiosis Meiosis is a special type of cell division that occurs in the sex organs of animals and plants. Meiosis results in the production of ova, which are eggs (singular ovum), in females and sperm in males.

Ova and sperm are also called gametes. Haploid gametes are produced from diploid cells. Meiosis requires 2 cell divisions which result in four daughter cells. Each daughter cell has half the

number of chromosomes as the parent cell. ( daughter cells are haploid , parent cell are diploid)

The Cell Cycle and Cell Division

Mitosis:

The process of cell division which results in the production of two daughter cells from a single parent cell The daughter cells are identical to one another and to the original parent cell Mitosis can be divided into stages

- Interphase- Prophase- Metaphase- Anaphase- Telophase and Cytokinesis

Interphase: The cell prepares for division- Cells that do not divide (nerves) are always in interphase- Hereditary information (DNA) copied (replicated /duplicated)- Period of growth and Development- Animal cell :

o DNA replicates o Organelles replicated o Cell increases in size

- Plant cell: o DNA replicated o Organelles replicated o Cell increases in size

Prophase: The cell prepares from nuclear division- Animal Cell:

o Packages DNA into chromosomes- Plant Cell:

o Packages DNA into Chromosomes Metaphase: The cell prepares chromosomes for division

- Animal Cell: o Chromosomes line up at the centre of the cello Spindle fibres attach to daughter cells to chromosomes at the centromere

- Plant Cell: o Chromosomes line up at the centre of the cello Spindle fibres attach to daughter cells to chromosomes at the centromere

Anaphase: The Chromosomes divide- Animal Cell:

o The chromosomes divide o Spindle fibres pull chromosomes aparto ½ of each chromosome (called chromotid - moves into each daughter cell)

- Plant Cell:o The chromosomes divide o Spindle fibres pull chromosomes aparto ½ of each chromosome (called chromotid - moves into each daughter cell)

Telophase:- Animal Cell:

o DNA spreads outo 2 nuclei form o Cell wall pinches in to form 2 new daughter cells

- Plant Cell:o DNA spreads outo 2 nuclei form o Cell wall pinches in to form 2 new daughter cells

Identify that information is transferred when DNA replicates:

Inside a nucleus are instructions for every part of the organism. Like a genetic Master Plan Before an instruction can be carried out, that particular part of the genetic master plan must be copied so that

the master plan can stay inside the nucleus These instructions code for the production of proteins which are an essential for the cell. Most genes code for

this To produce one of these proteins, certain enzymes ‘unzip’ that part of DNA coding for that particular protein so

that there is 2 sides of the ‘ladder’ Nucleotides on each side attract other free nucleotides in nucleus to make a copy of DNA sequence for the

production of that protein. This is called transcription. Copy of the DNA sequence is called messenger RNA. It passes through pores of nuclear membrane into the cytoplasm to the ribosomes – where the proteins are

made Code/messages for the making of the particular protein are carried in the messenger RNA RNA strand is different to the DNA, as the base THYMINE “T” is replaced with the base URACIL “U” Ribosomes – message is translated. Amino acids are collected from the cytoplasm and linked in sequence Therefore chains of amino acids make up protein molecules according to DNA instructions.

Allele, Hybrid, Pure-Breeding, Dominant, Recessive

Allele: one of two or more alternative forms of a gene, occupying the same position locus on paired chromosomes and controlling the same inherited characteristic

Are all the different variations of that characteristic. E.g. so all the hair colours, eye colours, tall/short. But we only have 2

Hybrid: The offspring of 2 animals or plants of different breeds, varieties, species or genera

Pure-Breeding: When an organism that has certain traits are passed on to all generations when bred with another true breeding organism for the same traits.

Dominant: A gene in one strand of DNA that is stronger than the corresponding gene in another strand of DNA

Recessive: A gene in one strand of DNA that is weaker than the corresponding gene in another strand of DNA

The roles of genetics and the environment in determining the features of an organism:

Genetics determine the features of an organism because that particular feature they carry are passed down from generation to generation thus being received and or shown on the organism

The environment determines that features of an organism because as the organism develops the features they received genetically change according to where they live (if they live in rough conditions or nice conditions determines their features) their unique experiences and also climatic factors

Evolution:Define the term Mutations and describe how mutations occur:

A mutation is a change in the chemical structure of the DNA that makes up the genes on a chromosome (gene mutation), or a change in the number or structure of the chromosome (chromosomal mutation)

Mutation can occur spontaneously e.g. due to errors in DNA replication, or they can be induced by a mutagen (environmental factor) such as radiation (e.g. X rays and UV Rays) or chemical agents (e.g. formalin and benzenes)

Mutations can result in changes in the proteins being made and thus changes in the cell activity. If the mutation is carried on the sperm or ova, it can be inherited by the offspring. Inherited gene and chromosome abnormalities result in genetic disorders

Describe the disadvantages of mutations and the advantages of DNA replicating:

Mutations: Some mutations are thought to have little or no effect on the survival of an organism of its ability to reproduce. They are not harmful or beneficial to the organism in which they occur. They may be very important in an evolutionary sense however. Even though a mutation has no ‘adaptive value’ for the organism at present, it may in the future. These so called ‘silent’ mutations are difficult to detect because they have no observable effect

DNA Replicating: DNA provides the instructions for building proteins. Proteins are very important to keep our body functioning properly. If the DNA sequence of a gene is altered or changed, then the protein produced by that gene may be faulty or absent, and as a result, the body will not be able to function properly.

Identify benefits of mutations:

Examples:

Antibiotic Resistance

- Some bacteria become resistant to antibiotics, with the result that many antibiotics are no ineffective

Harmful (Humans) /Beneficial (Bacteria)

Peppered Moths

- Stand out against the Lichens and are easily seen by predators. - Tree trunks blackened with soot = Blend in and protected from

predators.

Harmful/Beneficial

Sickle Cell Anaemia

- Red blood cells become distorted into a sickle (“C”) shape. - Shaped cells can no longer move easily through the blood. - Tend to clump and get stuck in blood vessels, causing a host of

problems. - Haemoglobin is abnormal and distorts the red blood cells to

their sickle shape. - Resistant to malaria

Harmful/Beneficial

The Blue Eyed Gene

- People have blue eyes Beneficial

Describe the theory of natural selection

EVOLUTION BY NATURAL SELECTION:- The main ideas behind the theory of evolution by natural selection are:1. For any given species of organism, more offspring are produced than can possibly survive2. Therefore within species there is competition for available resources – food, water, shelter, protection,

mating, etc3. Within any species there is variation between individuals – as a result of sexual reproduction.4. Survival of the fittest. This means that individuals with characteristics that give them a better chance of

survival in their environment will be more likely to survive and reproduce, and pass on these characteristics to their offspring.

5. The accumulation of small changes over long periods of time in stable environments can result in gradual changes to the species.

6. Sudden changes to environments may select different survival characteristics, resulting in the eventual development of new species and the extinction of less well adapted organisms.

Describe the theory of evolution and the evidence for it

Theories:

EVOLUTION BY INHERITANCE OF ACQUIRED CHARACTERISTICS:- Jean - Baptiste de Lamarck, a French scientist of the 18th century had the idea that characteristics

acquired by an organism during its lifetime were passed on to its offspring- So Lamarck would explain that giraffes have long neck because in each preceding generation, the giraffes

stretched their necks more and more to teach the tastiest leaves on the top of the trees. EVOLUTION BY NATURAL SELECTION:

- Charles Darwin, in the early 19th Century, came to the conclusion organisms evolve and new species appear over time by a process of Natural Selection

- He came to this conclusion as a result of what he saw in South America and other parts of the World during the voyage of the ship HMS Beagle, between 1831 and 1836. He was the ship’s naturalist.

- Environment changes. No need for species. This change causes a change of species in order to adapt to the environment.

- Alfred Wallace, working independently of Darwin in South East Asia and Indonesia, came to very similar conclusions as Darwin. Darwin published his ideas in a book called “On the Origin of Species by means of a Process of Natural Selection”, which was published in November 1859.

Evidence:

Fossil Evidence:

- Fossils of organisms show gradual change over time. For examples fossils over the last 60 million yeas clearly show the evolutionary changes in the ancestors of horses and modern horses.

Transitional Forms:- There have been many other discoveries of fossil organisms that show features that are intermediate

between primitive and more advanced forms. These are sometimes referred to as “missing links”. These fossils provide evidence that there has been gradual change in organisms over time, and that more recent organisms have evolved from more primitive organisms of the past.

- Example: Archaeopteryx, shows features of both reptiles and birds, and thus provides evidence of an evolutionary link between reptiles and birds.

- Tiktaalik; a recently discovered fossil is through to be a transitional form between fish and amphibians. Comparative Anatomy:

- Similarities of anatomical structures indicate evolution from a common ancestor. For example the arrangement of the bones in the limbs of vertebrates shows similarities that suggest that all vertebrates are descended from a common ancestor.

Comparative Embryology:- At very early stages of development all vertebrate embryos show similarities of structure. This suggests

once again that vertebrates are all descended from a common ancestor. Protein and DNA Analysis

- The % of similar proteins, or similar DNA sequences, gives an indication of how closely related different species are. This reflects how far back in time they separated from a common ancestor. It also aids in the construction of phylogenetic trees.

Geographical Distribution- The present distribution of organisms over the earth can be explained by evolution, combined with

continental drift. Isolation and Adaptation:

- To the local environment. Isolation keeps gene pools separate and therefore allows the selection of gene combinations that give the traits most suitable for survival in that particular environment. Example: Central American frogs on isolated islands and habitats.

Adaptive Radiation:- A population that is isolated will over time, evolve into many different forms to occupy all available

ecological fiches. Direct Evidence of Evolution

- Observations that illustrate how environmental factors select organisms with specific traits:- Peppered moths and industrial melanism: The peppered moth is a type of moth common in Europe and

England. These moths have speckled pattern on their wings so that they blend in with the speckled bark and lichens on tree trunks.

- Before the industrial revolution (early – mid 1800’s) the majority of these moths were pale coloured. His was because ant dark coloured moths stood out against the pale tree trunks and could easily be spotted and eaten by predatory birds.

- However, in industrial towns, factories burned coal to power the machinery, and black smoke caused trees and buildings to become dirty and black with soot.

Describe a genetic issue that has been in the mass media

Describe your issue: Gene Therapy is “the use of genes as medicine”. It involves the transfer of a therapeutic or working copy of a

gene into specific cells of an individual in order to repair a faulty gene copy. In gene therapy, only body (somatic) cells and not the egg or sperm cells (germ cells) are targeted for treatment.

It is a technique for correcting the genes that are defective responsible for diseases development. Most of the time, a “normal” gene is inserted into the genome in order to replace an “abnormal” gene which causes

disease. A vector which is a carrier molecule must be used to deliver therapeutic gene to the patient’s target cell. Currently the most common vector is a virus that has been genetically altered to carry normal human DNA.

Discuss societal, religious and ethical the implications: There are many pros and cons, or factors to consider before having gene therapy. Some may be devoted Catholics or strongly religious, or some may go against their morals. There are some ethical, religious and societal implications to consider before having the therapy.

Ethical:

The benefits and the risks of gene therapy for each individual must be weights. With the current technology, there exists a risk of infection by viral vectors, as well as the risk of disrupting a vital gene and causing another disease or a predisposition to cancer.

Somatic-cell gene therapy has been distinguished successfully from more plans for human gene engineering. What is exactly normal and what is a disability/illness/disorder, and who decides it? Will it be the patient,

the doctor the family etc Are disabilities seen as diseases? Should they be prevented or cured? Should it be left as it is.

Religious:

Would it go against individual’s religion to change something about them. Should the disability be accepted as who they are and to deal with it naturally? Are we suppose to be playing God, and altering genes? Some might say that no one should have the right in choosing the characteristics of a child, and to accept the

differences of a child whether good or bad, and it’s God’s decision in what the child is given, or in what you are given.

Everyone is made special and unique.

Societal:

Societal implications of gene therapy are that if there is fairness in the use of genetic information by insurers, employers, schools, adoption agencies, military etc.

If there is privacy and confidentiality of genetic information, who owns and controls the information given? How does the personal genetic information affect the individual’s and society’s perceptions

Describe how to verify the accuracy of media information about a scientific topic

Check if information is similar through more than 3+ sources (newspapers, internet, books)

Chemistry – The Inside Story:1. Describe the currently accepted model of the Atom:

- At the moment, the accepted model of an atom is that it consists of a small, dense nucleus made up of neutrons (uncharged particles) and protons (positively charged particles) that is surrounded by rapidly moving, negatively charged electrons.

- The neutrons and protons of a nucleus are tightly bound together. 2. Describe the features and locations of the following sub-atomic particles:

All matter is made up of small particles which we call atoms. Some atoms join together to form larger particles which we call molecules. If all the atoms in a particular molecule are the same, then we call this an

element. If the atoms are different, it is called a molecule of a compound. Atoms are made up of even smaller particles. There are many smaller particles which group together to form an atom.

Protons and neutrons make up the centre part of an atom, called the nucleus. Protons have a positive charge.

Neutrons and protons make up the centre part of an atom, called the nucleus. Neutrons are said to be neutral.

Electrons orbit around the nucleus of the atom. Electrons have a negative charge. Neutrons and Protons are both 1840 times heavier than the Electron.

Atoms in their normal state have no electrical charge. This is because they contain equal numbers of protons and electrons. The charges on the protons and electrons balance and make the atom neutral overall.

3. Distinguish between atoms of different elements based on the number of subatomic particles present.

Subatomic particles are particles that are smaller than the atom. The number of protons in an atom determines the identity of the element.

Examples: They are different because they have a different number of protons, neutron and electrons. Therefore, they are different elements:

Helium Atom:-- 2 protons- 2 neutrons- 2 electrons

4. Identify that an element may exist as different isotopes

When changes occur in substances atoms may lose electrons or gain electrons to form charged particles called ions.

While atoms of elements have equal numbers of protons and electrons, the number of neutrons in the atoms of particular elements can vary. This is how isotopes arise. For example, all atoms of oxygen have eight electrons and eight protons, and most oxygen atoms have eight neutrons. Some, however, have 10 neutrons. This means that there are two isotopes of oxygen.

Isotopes are the same element with different numbers of neutrons in their nucleus. This means that isotopes of the same element will have the same number of protons, but they will have different neutrons.

Some atoms of a particular element can have a different number of neutrons in their nucleus, giving them different mass numbers.

Different atoms of the same element are called ISOTOPES.

5. Describe the main historical models of the atom including the models proposed by Dalton, Thomson, Rutherford, Bohr and Chadwick.

Dalton:

1808: John Dalton’s atomic theory proposed that:- All matter consisted of tiny particles called atoms- Atoms could not be divided into smaller particles- Atoms of the same element were alike, but are different of those from any other element

By the end of the 19th century, many experiments were being done with a new invention called a cathode ray tube.

J.J Thomson: (Joseph John Thomson)

1897: English scientist Sir J. J. Thomson

Oxygen Atom-- 8 protons- 8 neutrons- 8 electrons

- Explained that the atom contained negatively Charged particles called electrons.- Discovered that these cathode rays were actually steams of negatively charged particles.- His model suggested that atoms were positively charged spheres with negatively charged electrons

embedded in them like the fruit in a plum pudding.

Lord Rutherford:

1911 (New Zealand)- Lord Rutherford proposed that the atom consisted mostly of empty space with a dense nucleus

containing positively charged protons in the centre. - Negatively charged electrons orbited the nucleus. Although Lord Rutherford’s model of the atom was

essentially the same as today’s accepted model, its one flaw was that it proposed that the orbiting electrons would eventually lose energy and spiral in towards the nucleus.

Niels Bohr:

1913: - Niels Bohr, a scientist who had studied with Rutherford, modified the model by suggesting that

electrons orbit the nucleus at different energy levels. Only electrons with specific amounts of energy could exist at each level.

- His model proposed that electrons could move from one level to another by gaining or losing ‘packets’ of energy.

- Although Bohr’s model explained why electrons did not spiral in towards the nucleus, it did not explain all of the known properties of atoms.

- He used evidence from spectroscopy of hydrogen atoms to propose that electrons are not just randomly situated around the nucleus- they are found at certain energy levels around the Nucleus, called ‘electron shells’. This was the start of the quantum Mechanical model of the atom, the basis of the current model.

Sir James Chadwick:

1932: - Sir James Chadwick discovered that the nucleus contained particles called neutrons, as well as

positively charged protons. - Neutrons had no electric charge and a mass about the same as a proton.

6. Explain why the model of the atom has changed over time.

The main factor has been the evolution of quantum physics. In the early days of research into the structure of the atom Niels Bohr proposed a simple model of the atom with orbiting electrons circling a central nucleus. Similar in fact to a miniature planetary system. As quantum theory matured so also did the concept of the atomic structure. The idea that electrons had well defined orbits was no longer compatible with the quantum viewpoint. The introduction of the uncertainty principle put paid to any notion of definite position at a precise time as did the observation that particles also displayed wave - like properties such as the diffraction of electron beams.The emerging science of particle physics and the implications of quark theory were also factors which hastened the demise of the old model

7. Describe how an idea can gain acceptance in the scientific community as either a theory or law.

Scientific Method

An approach to find out information: Involves 6 steps.

o 1. Making an Observation: the scientist notes something that gets him/her thinkingo 2. Asking a Question: the observation leads to the scientist asking questions.o 3. Forming A Hypothesis: using the observations- the scientist makes a general statement.

o 4. Making Predications: the scientist uses the general statement to make prediction about what should happen in a situation.

o 5. Testing The Hypothesis: the hypothesis can be tested experimentally if the experimental results agree with the hypotheses, more experimenting takes place. If they do not agree- the hypothesis must be changed.

o 6. Making a Conclusion: after much testing when the experiments repeatedly support the hypothesis, a conclusion is made. This means it is accepted as a good hypothesis, until it can be proved wrong. It does not mean the Hypothesis is a ’proven’ fact.

8. Describe the arrangement of electrons in the first 20 elements and relate this to the elements position on the periodic table.

Electrons are arranged in shells at different distances around the nucleus. As we move across each row of the Periodic Table the proton number increases by one for each element. This means the number of electrons also increases by one for each element .

Starting from the simplest element, hydrogen, and moving through the elements in order we can see how the electrons fill the shells. The innermost shell (or lowest energy level) of electrons is filled first. This shell can contain a maximum of two electrons.

Next, the second shell fills with electrons. This can hold a maximum of eight electrons. When this is filled, electrons go into the third shell, which also holds a maximum of eight electrons. Then the fourth shell begins to fill.

The table shows the number of electrons in each shell for the first 20 elements in the Periodic Table.

9. Explain the similarities in properties of elements in the same group of the Periodic Table.

- Group 1- has one outer shells- Group 2- has two outer shells- Group 3- has three outer shells- Group 4- has four outer shells

They have the same number electrons in outer shell

10. Describe the energy and particles that are released from nuclei of atoms during nuclear reactions:

Production:

- Changes can occur in the structure of the nuclei of atoms. These changes are called nuclear reactions. Energy created in a nuclear reaction is called nuclear energy, or atomic energy.

- Nuclear energy is produced naturally and in man-made operations under human control.

Naturally: Some nuclear energy is produced naturally. For example, the Sun and other stars make heat and light by nuclear reactions.

Man-Made: Nuclear energy can be man-made too. Machines called nuclear reactors, parts of nuclear power plants, provide electricity for many cities. Man-made nuclear reactions also occur in the explosion of atomic and hydrogen bombs.

Nuclear energy is produced in two different ways, in one; large nuclei are split to release energy. In the other method, small nuclei are combined to release energy.

Nuclear Fission: In nuclear fission, the nuclei of atoms are split, causing energy to be released. The atomic bomb and nuclear reactors work by fission.

Nuclear Fusion : In nuclear fusion, the nuclei of atoms are joined together, or fused. This happens only under very hot conditions

11. Discuss the benefits and problems associated with medical and industrial uses of nuclear energy.

- Group 5-has five outer shells- Group 6- has six outer shells- Group 7- has seven outer shells- Group 8/0- has 8 outer shells (full)

Benefits:

Industrial: - Nuclear power plants can provide a lot of energy from only a small volume of a source such as uranium. The

energy density of things like uranium is very high, compared to conventional things like coal. Medical: - Nuclear energy has long played a role within medical diagnosis and treatment processes.- Nuclear medicine can create a powerful light force, and is used to take pictures of the inside of the body.

Problems:

Industrial- - A problem associated with nuclear power plants is the waste they produce. Radioactive waste is very

hard to dispose of safely, since it may remain radioactive and hence a biohazard for many hundreds of years.

Medical - Nuclear energy is of course very dangerous to humans, resulting in loads of cancers and heart disease

etc. People working in a nuclear power plant, the technicians and engineers would not really be at risk unless the thing exploded or leaked, which is prevented by very strict safeguards. The handling of the nuclear waste material might be of concern, though. If people ever come into contact with it over a matter of decades or even hundreds or thousands of years, the radiation will create big medical problems.

12. Assess the reliability of gathered information.

Reliability of gathered information.

13. Analyse the accuracy of information presented in mass media.

Mass media refers collectively to all media technologies, including the Internet, television, newspapers, and radio, which are used for mass communications, and to the organizations which control these technologies.

Shapes public perceptions on a variety of important issues, both through the information that is dispensed and through the interpretations they place upon this information.

Shape modern culture, by selecting and portraying a particular set of beliefs, values, and traditions (an entire way of life), as reality. All information coming through the mass media can be filtered by the government or organizations and therefore mass media can be unreliable as we may not be getting the whole truth about a situation.

14. Construct an electronic database to tabulate information.

In other words it is a computer-based collection or listing of information, usually organized with searchable elements or fields.

On The Move:Define speed as the rate of change of distance:

- A measure of how fast an object is going or has gone. Rate of change of distance from one place to another. How far something travels in a certain time

- Measured in units like metres per second (ms-1), kilometres per hour (km/h) or centimetres per 100 years and so on.

Calculate the average speed of an object using the formula:

Average speed = distance and appropriate units time

Velocity:

- A measure of how fast and in what direction an object is going or has gone. Rate of change of displacement- Measured in the same units as speed but the direction in which the object is moving MUST be included

o Average speed: total distance travelled/time taken Speed = m/s Time = s Distance = m

Use appropriate equipment to measure the average speed of an object:

Stop Watch (Measure time taken); Tape Measure/Ruler (distance between points. Etc

Define Acceleration as the rate of change of speed and/or direction:

- Tells us how quickly something is changing velocity- Is the rate of increase of velocity - The rate of change of speed and or direction

o Acceleration = change in velocity (speed) / time taking to change velocity Acceleration = m/s/s = m/s2

Velocity= m/s Time= s

Read and interpret distance/time and speed/time graphs.

Newton’s Law:

First Law: INERTIA

- A body wants it keep doing what it is doing. This means that a moving body wants to continue moving in a straight line, while a stationary body wants to remain stationary

- The law states that an object that is moving will continue to move at the same speed and in the same direction – unless a new force is acting on it.

D

S T V

D

T

A = ∆V / ∆T

o Average Velocity: Displacement/ Time Taken

Velocity: m/s Time: s Displacement: m

- An object that is at rest will remain at rest, or an object that is moving will continue to move in a straight line with constant velocity, if and only if the net force acting on the object is zero.

o E.g. Accelerator in a car: When the car accelerates forward, we want to stay at the same speed. When the car accelerates at the speed you get pushed back, and so while the car continues to move due to the force, you want to remain stationary unless a force makes you move.

o The car has a net force and it is pushing the car forward therefore the car is accelerating, and since you are in the card you are pushed back remaining stationary.

Third Law: ACTION – REACTION

Newton’s third law stated that every action force has an equal but opposite reaction force. “For every action there is an equal but opposite reaction.”

- Whenever one object exerts a force on a second object, the second exerts an equal and opposite force on the first

- One of the forces is not obvious and may be overlooked entirely o Relate to a car: Safety measures of a car – You are pushing into the seatbelt and the seatbelt is

pushing into you. Headrest: Your inertia wants you to rock your head back, so when your head goes back the force of the headrest to you equalled to the force of you pushing into the headrest.

Net Force:

Net force is the unbalanced force acting on an object. When two or more forces act on an object, the resultant (vector sum) of the forces is the net force.

More than one force can act on an object at once. E.g. two people could push on a book at the same time (left and right). Two forces would act against each other. Force = difference between the strengths of the two separate forces. In this prevailing force is called the net force. Basically, the word net means total.

If one person pushed the book with a force of 20 Newtons toward the left, and the other person pushed the book with a force of 18 Newtons toward the right, then that the net force would be 2 Newtons in size and directed toward the left.

Same strength = the two forces cancel each other out. The net force on the book would be 0 Newtons (object are balanced/ equilibrium). Object will not

accelerate. Velocity of object will not change.

Mass & Weight:

Second Law: F = MA

F = m . a (m x a) - Second law is about acceleration: acceleration makes

an object go faster or slower, or change its direction. The acceleration of an object depends on the force acting on it and its mass.

- When the net force acting on an object is not zero = object accelerates at the direction of the exerted force. The acceleration is directly proportional to the net force and inversely proportional to the mass

- Formula – Acceleration = force/mass or a=f/m

Thrust

Downwards Push

Resistance (Friction)

Upwards Push

Calculate mass and acceleration using the formula F = ma.

When an object changes speed (accelerates or decelerates),its shape or direction of motion, a force is acting on it. The formula for force is:

F=mass(kg) X acceleration(m/s/s)The unit of force is called the newton.=> A 100 kg person standing on wooden floor boards exerts a force of 1000 newtons on the floor.

- Mass: Is the resistance of an object to acceleration. It is an intrinsic property of an object. The property of an object that is a measure of its inertia, the amount of matter it contains, and its influence in a gravitational field.

- Weight: The vertical force experienced by a mass because of gravity. The quality of heaviness in things, determined by their mass or quantity of matter as acted on by the force of gravity, that counteracts efforts to lift or move them

- To clarify the difference, suppose we take an object to the Moon. There it will weight a sixth of its weight on Earth, but its mass will remain the same.

Outline the work of Galileo and Newton in the development of the laws of motion.

Galileo had proved that the planets revolve around the sun, not the earth as people thought at the time. Isaac Newton was very interested in the discoveries of Galileo and others. Galileo had discovered inertia and Newton formed the first law of motion by using what Galileo had come up with about inertia.

Energy E Joules, J E = QV or V=E/QE= Pxt or E= IVtTime t Seconds, s

Force F Newtons, N F=maMass M Kilograms, kgWeight (a force) W Newtons, N W = mgVelocity or Speed V or s Metres/sec, m/s S = d/tAcceleration A Metres/sec2, m/s2 a =^/t or a= f/mWork done Wd Joules, J Wd = f x dPotential Energy PE Joules, J P= Wd / tKinetic Energy KE Joules, J KE = 1/2mv2

ENVIRONMENT AND RESOURCES1. Define the term ‘Ecosystem’.

A community of living things that interact with each other, and with the environment in which they live.2. Distinguish between abiotic and biotic features of ecosystems, giving examples.

ABIOTIC: Non-livingBIOTIC: LivingThe ABIOTIC features refer to the non-living parts where as BIOTIC features refer to the living parts (biological parts) of an ecosystem. In other words, the interactions of living things.

ABIOTIC FEATURES BIOTIC FEATURESWind speed and direction. Competition for food and water.Water quality (e.g. salinity, turbidity, pH, dissolved oxygen levels) and water temp.

Competition for mating.

Air quality, temp and relative humidity. Competition for living space and shelter.Soil quality (e.g. sandy, clayey) moisture levels, aeration, soil pH and temp.

Predation, including relative abundance of predator and prey.

Pollution levels. Beneficial interaction (e.g. mutualism, commensalism) and parasitism.

Light intensity.Rainfall levels.

3. Identify the roles of producers, consumers and decomposers in ecosystems.

PRODUCER: an organism that makes its own food by the process of photosynthesis using the suns energy and carbon dioxide and water from the environment. This takes place in the chloroplasts containing chlorophyll e.g. a plant.CONSUMER: an organism that relies on other organisms for its food. It may feed on plants or other animals.DECOMPOSER: a small organism that breaks down dead and decaying matter e.g. bacteria and fungi.

4. Construct and interpret food chains and food webs.CONSTRUCT A FOOD CHAIN:

I. Start with the producerII. Point the arrows in the direction that the energy and matter flow

E.g. grass grasshopper magpie

INTERPRET A FOOD CHAIN:

From example: The grass is the producer and is eaten by the grasshopper which is a first order consumer and a herbivore. The magpie eats the grasshopper and it’s a second order consumer and a carnivore.

CONSTRUCT A FOOD WEB:

I. Place the PRODUCERS at the BOTTOMII. Group the consumers according to their trophic (feeding) level and

place in order from lowest to highest level up the page.

*NOTE: some organisms often occupy more than one trophic level, so it is not always possible to adhere strictly to this pattern.

INTERPRET A FOOD WEB:

Food webs can be used to explain and predict changes in the community.

E.g. a farmer may want to eliminate foxes (predators) from the community because they prey on sheep. However, from the food web, it can be seen that the destruction of the fox (predator) population may not be in the farmer’s interest. The elimination of foxes could also lead to an increase in the population of pests (e.g. insects, mice and rabbits). These may in turn, eat more grass and reduce the amount of fodder available to sheep. It may be that the presence of the foxes in the ecosystem actually increases the productivity of the farm.

NOTE:

If the predator (fox) numbers increase, the sheep (prey) numbers will decrease. If the predator (fox) numbers decrease, the sheep (prey) numbers will increase. If the prey (sheep) numbers increase, the producer numbers will decrease. If the prey (sheep) numbers decrease, the producer numbers will increase.

5. Describe the flow of matter and energy through food chains and webs.FLOW OF ENERGY IN A FOOD CHAIN/WEB:

The energy flowing in a food chain originally comes from the SUN PHOTOSYNTHESIS is important in bringing energy into a food chain, converting solar energy into

chemical energy RESPIRATION is the process by which the consumers release energy from the food they eat.

Respiration is important in converting chemical energy into kinetic energy and heat energy

FLOW OF MATTER IN A FOOD CHAIN/WEB:

Matter (food) flows from the producer to the first order consumer to the second order consumer to the third order consumer along a food chain in a food web

Chlorophyll

Sunlight

Chlorophyll

Sunlight

EXTRA INFORMATION:

EQUATION FOR PHOTOSYNTHESIS-

Carbon Dioxide + Water

6CO2 + 6H20

EQUATIONS FOR RESPIRATION-

Glucose + Oxygen

C6H12O6 + 6O2

6. Describe the water, carbon-oxygen and nitrogen cycles and describe their importance.

The Water Cycle:

- Water is a finite (limited) resource and therefore it is imperative that it is cycled, this happens naturally by 3 processes:1. Evaporation (Liquid Water Water Vapour)

Heat2. Condensation (Water Vapour Liquid Water

Cools3. Precipitation (Liquid Water Falls

Clouds become heavy with water therefore = Rain

- Evaporation from the lakes, oceans and streams are exposed to heat, which then turns the liquid water into water vapour.

- The water vapour cools down and condenses and one the water in clouds become too heavy due to the liquid water collected, precipitation occurs and there is rain.

The Carbon Cycle:

- The amount of carbon dioxide in the atmosphere is limited and is only about 0.03% therefore it is important for the carbon cycle to occur naturally

- It occurs due to the following 4 processes:1. Photosynthesis2. Respiration3. Decomposition 4. Combustion

- Photosynthesis: Carbon Dioxide in the atmosphere with water is taken in by the plants. Due to their presence in the sunlight, they with chlorophyll create their food; glucose. In the food web, plants are eaten by the animals, and that is how animals obtain their carbon. Herbivores obtain carbon through plants and carnivores obtain their carbon through eating other

animals

C6H1206 + 602

Glucose + Oxygen

Carbon Dioxide + Water + Energy

6CO2 + 6H2O + 38ATP

- Respiration: When animals breathe they release the carbon back out into the atmosphere. During respiration

- Decomposition: When animals and plants die, their decay / matter contains C02 and these form fossil fuels

- Combustion: The fossil fuels are taken and burned to use in fuels which carbon is then released into the atmosphere.

Carbon dioxide is then taken in by plants, and the cycle starts again. - Carbon Dioxide is absorbed in plants through photosynthesis to produce carbohydrates. - Plants are eaten by animals and when they respire carbon is released into atmosphere- When animals and plants decay, they produce carbon dioxide in fossil fuels (coal + oil)- Carbon is then released back into the atmosphere though combustion of fossil fuels.

The Nitrogen Cycle:

78% of the atmosphere is nitrogen. Even though it is very abundant, nitrogen is finite and it is necessary for it to be recycled.

Nitrogen is taken from the atmosphere into the soil, through lightning and nitrogen firing bacteria. Nitrates are absorbed by the plants and then they are transferred when herbivores eat the plants, and

transferred again when the carnivores eat other animals. When all 3 (plants, herbivores, carnivores) die, the nitrogen is transferred to decomposers. Ammonium is

then absorbed by nitrifying bacteria which converts it into nitrite. Nitrite is then converted to Nitrates through the nitrifying bacteria. Finally denitrifying bacteria returns the

nitrogen back to the atmosphere, where the cycle starts again. 7. Define the term biodiversity and explain why biodiversity is important.

Biodiversity:

Biodiversity (biological diversity) refers to the variety of life forms. The different plants, animals and microorganisms, the genes they contain and the ecosystems they form.

It is the variety of all living organisms found on earth.

3 Levels of Biodiversity:

1. Genetic Diversity:- Refers to the variety of genetic information contained in all of the individual plants, animals and

microorganisms. - Occurs within and between populations of species as well as between species - Variation in the genes found within a species2. Species Diversity:- Variety of living species- Variety in the types of plants, animals and microorganisms found3. Ecosystem Diversity:- Variety of different environments that support different species.- Variety of habitats, biotic communities and ecological processes as well as tremendous diversity present

within ecosystems in terms of habitat differences and the variety of ecological processes.

Why it is so important?

Human beings depend on biological systems and processes for their sustenance, health, well-being, and enjoyment of life

Humanity derives all of its food and many medicines and industrial products from the wild and domesticated components of biological diversity.

Biotic resources serve recreation, tourism which provide us with many services:

Ecosystem Services:

Soil Formation and Protection: Protection of water resources: Nutrient storage and cycling: Pollution Breakdown and absorption: Contribution to climate stability: Providing natural pest control: Recovery from unpredictable events: 8. Discuss the importance of energy as a resource for humans.

Humans need energy resources to maintain their standard of living:

1. To provide heat and energy for their personal needs (e.g. heating, lightning, cooking)2. To power their machines (e.g. machines used in industries, factories, offices) Energy supply, long or short term, is needed for both the economic development and people’s quality of life,

as well as protecting the environment. There is also a need for a greater diversification of energy resources. It is necessary for us to be able to achieve work more efficiently and quickly. Some may be a natural resource – a resource which is obtained from the environment and not made by

humans E.g. Fossil Fuels, uranium Some may be resources extracted from the earth, air or oceans and some may be renewable energy - Earth : Fossil Fuels - Air: Wind Energy- Oceans: Oil and Natural Gas, wave energy, tidal energy Some may be resources made from living things: Biofuels (fuel made from plant and animal tissue/fuel

from biomass) Biogas or Ethanol from sugarcane 9. Distinguish between renewable and non-renewable energy sources, giving examples.

RENEWABLE ENERGY SOURCES:Energy resources that will not become depleted over time as they can be readily replaced are called renewable energy resources.EXAMPLES OF RENEWABLE ENERGY RESOURCES

Solar Energy- energy in the sun Wind Energy- kinetic energy in moving air Wave Energy- kinetic energy in moving water Tidal Energy- kinetic energy in tides

NON-RENEWABLE ENERGY RESOURCES:

Energy resources that will become depleted over time as they cannot be readily replaced are called non-renewable energy resources. (They are used faster than they are produced)

EXAMPLES OF NON-RENEWABLE ENERGY RESOURCES

Energy from fossil fuels (e.g. coal, natural gas, oil)

10. Identify resources that are useful to humans, how they are obtained and the properties that make them useful.RESOURCES THAT ARE USEFUL TO HUMANS:E.g. 1. Fossil Fuels 2. UraniumHOW FOSSIL FUELS AND URANIUM ARE OBTAINED:

Biological resources:

1. Food:2. Medicinal resources:3. Wood products:4. Future resources:

Social Benefits:

1. Research, education and monitoring:

2. Recreation:3. Culture values:4. Benefits of timely action

1. Fossil Fuels- Obtained from the earth’s lithosphere by mining.2. Uranium- Obtained from the earth’s lithosphere by mining.THE PROPERTIES OF FOSSIL FUELS THAT MAKE THEM USEFUL AND ECONOMICALLY IMPORTANT: Fossil Fuels are combustible- i.e. they provide energy that can be harnessed for electricity etc. Fossil Fuels are presently available in the Earth’s lithosphere.THE PROPERTIES OF URANIUM THAT MAKES IT USEFUL AND ECONOMICALLY IMPORTANT: It can be converted in nuclear power stations into usable forms of energy. Uranium is available in Australia and can be mined and obtained from the Earth’s lithosphere. Uranium is exported from Australia to Europe and USA and is therefore a good source of revenue.

11. Describe examples in which technology has increased the variety of made resources.

12. Describe the causes and effects of pollution on the environment and relate this to the way humans acquire, use and dispose of resources.WASTES are produced when resources are used.POLLUTION refers to ‘contamination by unwanted substances’.E.g. the release of excessive amounts of Carbon Dioxide when fossil fuels are burnt.Carbon + Oxygen

TYPES OF ENVIRONMENTAL POLLUTION:

1. LAND POLLUTION2. WATER POLLUTION3. AIR POLLUTION

Humans often harm ecosystems and upset the balance of nature due to their activities. The following table shows examples of human activities and their impacts on ecosystems.

ACTIVITY IMPACT ON ECOSYSTEMMining Destroys native habitats and native organisms

Organisms may become endangered or extinct Increase soil erosion and degradation Can result in salination (excess salt) Can result in pollution (due to wastes)

Excessive Burning of Fossil Fuels

Pollution Acid rain and its consequences Enhanced greenhouse effect and its consequences

Disposal of Wastes PollutionAcid Rain:

Acidic gases (such as sulphur dioxide) from factories and metal smelters cause damage to ecosystems by the formation of acid rain.

Acid rain is formed when acidic gases dissolve in raindrops. Acid rain can leach valuable minerals from soils and so plants will not grow Acid rain damages tree leaves so they cannot photosynthesise Lakes and rivers can also become so acidified that fish eggs will not hatch

Pollution Due to Wastes:

The wastes that humans generate can pollute the natural environment Sewerage outfalls pollute the water in which aquatic organisms live If these wastes contain heavy metals (such as Mercury) or toxic compounds (such as Pesticides or

Herbicides), then organisms low on the food chain absorb these pollutants and pass them onto organisms higher up in the food chain

Carbon Dioxide

Due to this their concentration becomes magnified This is called BIOMAGNIFICATION

LOOK OVER ACTIVITY13. Discuss ways to minimise pollution.

Increase ventilation by opening doors and windows and using exhaust fans to keep chemical and gas fumes circulating out of the home. Clean the home thoroughly. Vacuuming more frequently and washing bed linens and stuffed toys regularly. Drive, smart vehicles. – Hybrid or Electric Vehicles or those which are environmentally friendly and will help prevent pollution. Even shopping for a gasoline-fuelled care with lower emissions. Minimise vehicle use. Ride a bike, use public transport, or carpool. Plant trees and plants. These take out carbon from the environment and the air we breathe. Reuse and recycle.

14. Describe the natural greenhouse effect. The Earth is surrounded by a giant invisible ‘blanket’ called the ‘atmosphere’ The atmosphere and surface of the Earth is heated by energy from the sun- solar energy The atmosphere emits heat because it is warm While much of the heat is radiated back into space, some of it is radiated towards the surface. This happens

because the Earth’s atmosphere contains gases called greenhouse gases (e.g. carbon dioxide, methane, nitrogen oxides) that trap some of the energy leaving Earth’s surface

This keeps the temperature of the Earth’s surface within a range that supports life This warming of the Earth’s surface by the atmosphere is called the greenhouse effect and it is necessary to

support life on Earth

15. Relate the use of fossil fuels to the enhanced greenhouse effect.The Enhanced Greenhouse Effect:Due to human activity such as… The burning of fossil fuels such as coal, gas and oil, that produce the gas Carbon Dioxide The use of aerosols, refrigerants and air-conditioners, the production of plastic and foam, and dry

cleaning products that produce CFCsThere is an increased amount of greenhouse gases in the atmosphere.

The result is an increase in the amount of energy trapped in the atmosphere, and an increase in the temperature of the atmosphere. This in turn has caused an increase in the temperature of the Earth’s surface.ENHANCED GREENHOUSE EFFECT- the increased warming of the Earth’s temperature due to the increased amount of greenhouse gases in the atmosphere.

HUMAN SCTIVITIES SUCH AS THE BURNING OF FOSSIL FUELS

INCREASED AMOUNTS OF GREENHOUSE GASES IN THE ATMOSPHERE

INCREASE IN THE AAMOUNT OF ENERGY TRAPPED IN THE ATMOSPHERE

INCREASE IN THE TEMPERATURE OF THE ATMOSPHERE

INCREASE IN THE TEMPERATURE OF THE EARTH’S SURFACE

ENHANCED GREEENHOUSE EFFECT/GLOBAL WARMING

Greenhouse Gas Main SourcesCarbon Dioxide Burning of Coal

Methane Livestock such as cows, rice, miningCFCs Aerosols, refrigerants in refrigerators and air

conditioners, the production of plastic foam, dry cleaning

Nitrous oxides Fertilisers and the burning of fossil fuels

POSSIBLE CONSEQUENCE OF THE ENHANCED GREENHOUSE EFFECT:1. Worldwide changes in weather patterns2. Gradual melting of ice caps3. Rise in sea levels

STRATAGIES TO REDUCE THE AMOUNT OF GREENHOUSE GASES:

Conserving the amounts of energy we use Planting trees to use more carbon dioxide (plants use carbon dioxide for photosynthesis) Reduce the burning of fossil fuels Reduce the cutting down of trees to make more new paper and reducing the use of paper, recycling

newspapers and other paper, and using recycled paper The use of alternative energy sources such as wind, water and solar energy16. Describe the potential uses of alternative energy sources.

Alternative or renewable energy sources show significant promises in helping to reduce the amount of toxins that are by-products of energy use. Oil reserves won’t last foreverThey protect against harmful by-products, but using alternative energy helps to preserve many of the natural resources that we currently use as sources of energyNeeded to take the burden off current dependency on fossil fuels and the level of fossil fuels products burnt each and every day which pollutes the air and surrounding environments. Alternative sources may help in improving quality of environment and air we breathe. Wind Power: Wind Energy harnesses the power of the wind to propel the blades of wind turbines. The rotation of turbine blades is converted into electrical current by means of an electrical generator. The produce no pollution that can contaminate the environment, since no chemical processes take place, like in the burning of fossil fuels. No harmful by-products left over. Solar Power: Renewable resource, as long as the sun exists, its energy will reach the early.

Generation releases no water or air pollution, because there is no chemical reaction from combustion of fuels. Can be used efficiently.

17. Define sustainability.SUSTAINABILITY: Development which meets the needs of the present without compromising the ability of future generations to meet their own needs.

18. Outline the principles of sustainable development. Do not compromise the possibilities of future generations through unsustainable practices Encourage consideration of alternative and more sustainable solutions strategies and perspectives in

addressing concepts, problems or issues in business, government and communities. Play an active role in promoting more sustainable practices Recognise your ability to act sustainably in all you do Through education, promote a behavioural change which exemplifies sustainable practices

*JUST SOME EXTRA DEFINITIONS JUST ICASE THEY SPRING IT ON THE TEST

RESOURCES- A country's collective means of supporting itself or becoming wealthier, as represented by its reserves of minerals, land, and other assets

CFCs- industrial synthetic chemicals containing chlorine, fluorine and carbon GLOBAL WARMING-A gradual increase in the overall temperature of the earth's atmosphere generally

attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants. OZONE LAYER-A layer of oxygen formed naturally, in the stratosphere, which acts as a screen to protect

plants and animals for the sun's harmful ultraviolet rays.

Chemical Reactions:1. Compare a physical change with a chemical reaction.

- A Physical change does not produce a new substance. Changes in state or phase (e.g. Ice Melting, freezing, vaporisation, condensation, sublimation etc) The starting and ending materials of a physical change are the same even though they might seem different.

- A Chemical change takes place on the molecular level. It produces a new substances (e.g. combustion, cooking an egg, mixing hydrochloric acid and sodium hydroxide)

2. Describe some indicators of a chemical reaction.- Fizzing- Light - Heat- Colour There will be significant energy changes, observed as changes of temperature, or in the case of combustion

reactions, as visible flames.3. Identify the reactants and products in chemical reactions.

Chemical equations uses chemical symbols for reactants and products to describe a chemical change

Reactants ProductsHydrochloric Acid + Sodium Hydroxide Sodium Chloride + Oxygen + Water

Reactants are the materials that are present at the beginning of a reaction. Reactants are written on the left hand side of the equation arrow

Products are the materials formed in a chemical reaction. Products are written on the right hand side of the equation arrow.

4. Explain what is meant by the Law of Conservation of Mass States that mass is neither created nor destroyed in any ordinary chemical reaction.

- Gas production (bubbles if in liquid)

- Odour - Sound

Reactant substance(s) will “disappear” or be eaten away.

New substance(s) will appear. Precipitates may occur in a solution

The mass of substances produced (products) by a chemical reaction is always equal to the mass of the reacting substance (reactants)

5. Compare endothermic and exothermic reactions and give examples of each type. Exothermic Reactions release energy because the products contain less Chemical Potential Energy than the

reactants. Because the chemicals lose energy, the energy change (H) is negative. Endothermic Reactions are those that require energy to proceed. The products have more Chemical

Potential Energy than the reactants. Since the chemicals have gained energy, (H) is considered positive.6. Identify a range of common compounds using their common names and chemical formulae.

Class Compound Formula Class Compound Formula

Gases

Oxygen O2 Phosphoric acid H3PO4

Nitrogen N2 Carbonic acid H2CO3

Hydrogen H2

BasesSodium hydroxide NaOH

Carbon dioxide CO2 Potassium hydroxide KOHCarbon monoxide CO Calcium hydroxide Ca(OH)2

Sulfur dioxide SO2

Salts

Sodium chloride NaClNitrogen dioxide NO2 Sodium carbonate Na2CO3

Nitrogen monoxide (nitric oxide) NO Calcium carbonate CaCO3

Dinitrogen oxide (nitrous oxide) N2O Calcium sulfate CaSO4

Chlorine Cl2 Ammonium sulfate (NH4)2SO4

Hydrogen chloride HCl Potassium nitrate KNO3

Ammonia NH3

AcidsHydrochloric acid HClSulfuric acid H2SO4

Nitric acid HNO3

7. Write word equations from observations and written descriptions of a range of chemical reactions.Reactants Products

Carbon + Oxygen (Hydrocarbon + Oxygen)

Carbon Dioxide Carbon Dioxide + Water

Calcium Carbonate + Hydrochloric Acid CaCo3 + HCL

Calcium Chloride + Carbon Dioxide + WaterCaCl2 + CO2 + H2O

Nitric Acid + Sodium Hydroxide Sodium Nitrate + WaterZinc + Copper Sulphate Zinc Sulphate + Copper

Lead Nitrate + Potassium Iodide Potassium Nitrate + Lead Iodide Sulphuric Acid + Magnesium Magnesium Sulphate + Hydrogen

8. Write and Balance simple equations.Examples: 1. 4Al + 3O2 2Al2O3

2. 2Cu + O2 2CuO3. 2Al + 3S 2Al2S3

4. 4Na + O2 2Na2O

9. Identify everyday examples of and describe reactants and products in the following chemical reactions: combustion combination corrosion precipitation decomposition

10. Predict the names of salts produced in examples of the above reactions.11. Write chemical formulae for ionic compounds.

Group I ions (alkali metals) have +1 charges. Group 2 ions (alkaline earth metals) have +2 charges. Group 6 ions (nonmetals) have -2 charges. Group 7 ions (halides) have -1 charges.

Lithium has a +1 charge and oxygen has a -2 charge, therefore2 Li+ ions are required to balance 1 O2- ion

Nickle has a charge of +2 and sulfur has a -2 charge, therefore1 Ni 2+ ion is required to balance 1 S2- ion

Bismuth has a +3 charge and Fluorine has a -1 charge, therefore1 Bi3+ ion is required to balance 3 F- ions

Magnesium has a +2 charge and chlorine has a -1 charge, therefore1 Mg2+ ion is required to balance 2 Cl- ions

12. Explain what a precipitate is.Precipitation is the formation of a solid in a solution or inside another solid during a chemical reaction or by diffusion in a solid.

13. Use the solubility rules to decide if a compound is soluble or insoluble and predict the products of reactions between different aqueous solutions.

14. Describe some factors (including catalysts) affecting

the rates of chemical reactions. Temperature: When you raise

the temperature of a system, the molecules bounce around a lot

more (because they have more energy). When they bounce around more, they are more likely to collide. That fact means they are also more likely to combine. When you lower the temperature, the molecules are slower

and collide less. That temperature drop lowers the rate of the reaction.  Concentration If there is more of a substance in a system, there is a greater chance that molecules will collide

and speed up the rate of the reaction. If there is less of something, there will be fewer collisions and the reaction

will probably happen at a slower speed.  Pressure: Pressure affects the rate of reaction, especially when you look at gases. When you increase the

pressure, the molecules have less space in which they can move. That greater concentration of molecules increases the number of collisions. When you decrease the pressure, molecules don't hit each other as often. The lower pressure decreases the rate of reaction.

Physical State: If particles are in the same phase (liquid/liquid)/(gas/gas) then it is very easy for them to mix with each other. Giving particles maximum opportunity o collide.

1. Li2O

2. NiS

3. BiF3

4. MgCl2

Lead Nitrate + Potassium Iodide Yellow SolidSilver Nitrate + Sodium Chloride Cloudy (Silver Chloride)