class: name: date: 11 cell cycle and divisionbio662.dyndns.info/dse/ws/ws_ch11_e.pdf · new senior...

Class: Name: ( ) Date:

New Senior Secondary Mastering Biology Oxford University Press 2015 (Second Edition)

- 1 -

11 Cell cycle and division

11.1 Chromosomes (Book 2, p. 11-3)

� (1) _______________ _______________ (細胞分裂) is a process in which a cell

((2) _______________ cell) divides to form new cells ((3) _______________ cells).

� Cell division involves the passing on of (4) _______________ information from parent cells to

daughter cells. This information is important in determining the structure and functions of

the cells and is carried in (5) _______________ _______________ (DNA). Inside the nucleus,

DNA and proteins together form structures called (6) _______________ (染色體).

� When a cell is not dividing, individual chromosomes are not visible. They exist as a mass of

long and thin fibres called (7) _______________ (染色質).

� At the time cell division begins, the chromatin fibres coil up tightly. Each chromosome is seen

to consist of two identical (8) _______________ (染色單體).

(10) _______________ fibre

DNA molecule

protein

a (9) _______________

▲ Structure of a chromosome at the time cell division begins

two (12) _______________ _______________

(姊妹染色單體) make up one chromosome

(11) _______________

(著絲點)


- 2 -

� Chromosomes exist in pairs called (13) _______________ _______________ (同源染色體) in

body cells.

- One member in a homologous pair comes from the male parent and is called the

(14) _______________ _______________ (父系染色體).

- The other one comes from the female parent and is called the (15) _______________

_______________ (母系染色體).

� Each body cell has (16) _______________ sets of chromosomes and is described as

(17) _______________ (二倍體) (2n).

� A gamete (配子) has (18) _______________ set of chromosomes and is described as

(19) _______________ (單倍體) (n).

� The (20) _______________ of chromosomes is always the same among individuals of the

same species but it varies from one species to another.

11.2 The cell cycle and mitotic cell division (Book 2, p. 11-6)

� Many body cells can divide by (1) _______________ _______________ _______________

(有絲細胞分裂). The (2) _______________ _______________ (細胞週期) is the sequence of

events that takes place in a body cell from one cell division to the next.

A What are the stages of the cell cycle? (Book 2, p. 11-6)

Stage Description

(3) _______________ (間期) It is also called cell growth.

Mitotic cell division It consists of (4) _______________ division and

(5) _______________ division.

1 Interphase (cell growth)

� Many biochemical activities take place to prepare for cell division, including:

- synthesis of new (6) _______________ and proteins.

- DNA (7) _______________ (複製). Each chromosome becomes duplicated (複製) and it

consists of (8) _______________ identical DNA molecules.

- the growth of cell to its (9) _______________ size.

� Chromosomes are (10) _______________ (visible / invisible) at this stage.


- 3 -

2 Mitotic cell division

� A body cell divides to form (11) _______________ daughter cells. The daughter cells

contain the same (12) _______________ and (13) _______________ of chromosomes as

their parent cell.

i) Nuclear division

� The nuclear division of mitotic cell division is called (14) _______________ (有絲分裂).

It involves the separation of the (15) _______________ _______________ of each

chromosomes and the equal (16) _______________ of the separated chromatids between

two daughter nuclei.

� Mitosis can be divided into four stages:

Stage Description

�

(17) _______________

(前期)

� Chromosomes shorten and thicken. They

become (18) _______________.

� The (19) _______________

_______________ breaks down.

�

(20) _______________

(中期)

� The chromosomes line up along the

(21) _______________.

� (22) ______________ ______________

(紡錘絲) attach to the chromosomes.

�

(23) _______________

(後期)

� The spindle fibres (24) _____________.

The (25) _______________

_______________ separate and move to

opposite poles of the cell.

� The (26) _______________ starts to

divide.

�

(27) _______________

(末期)

� New (28) _______________

_______________ form around each

group of chromosomes.

� The chromosome uncoil to become

(29) _______________ again.


- 4 -

ii) Cytoplasmic division

� Cytoplasmic division is also called (30) ______________ (胞質分裂). The (31) _____________

of the parent cell divides into two equal halves, forming two daughter cells.

� In animal cells, the cell membrane around the centre of the cell (32) _______________

inwards until the cell separates into two.

cell membrane

constricts inward

▲ Cytoplasmic division in animal cells

� In plant cells, a (33) _______________ _______________ (細胞板) is formed between

the two daughter nuclei. It grows outwards from the centre of the cell, dividing the

(34) _______________ into two halves.

cell plate

grows outwards

▲ Cytoplasmic division in plant cells

B What is the importance of mitotic cell division? (Book 2, p. 11-11)

� Mitotic cell division produces daughter cells that are genetically (35) _______________

_______________ (identical to / different from) their parent cell.

� Mitotic cell division is important for growth, repair and (36) _______________ reproduction

(無性生殖).

� Go to

Practical 11.1 Examination of different stages of the cell cycle

(Book 2 p. 11-10; Practical Workbook for SBA 2, p. 11-1)

Practical 11.2 Investigation of the relative time spent in each stage of the cell cycle



- 5 -

11.3 Meiotic cell division (Book 2, p. 11-13)

� (1) _______________ _______________ _______________ (減數細胞分裂) occurs only in

gamete-producing cells and results in the formation of (2) _______________.

� Meiotic cell division reduces the chromosome number by (3) _______________.

It gives rise to (4) _______________ haploid daughter cells which are genetically

(5) _______________ _______________ (identical to / different from) the parent cell and

among themselves.

A How does meiotic cell division occur? (Book 2, p. 11-13)

� Meiotic cell division occurs after (6) _______________. It consists of first meiotic division

and second meiotic division. Each of them starts with nuclear division ((7) _______________

(減數分裂)), followed by cytoplasmic division.

� First meiotic division involves the pairing and separation of (8) _______________

_______________. Second meiotic division involves the separation of the

(9) _______________ _______________ of each chromosome.

� Stages of first meiotic division:

Stage Description

�

Prophase I

� Chromosomes shorten, thicken and become visible.

� Members of each pair of (10) _______________

_______________ pair up.

� The nuclear membrane breaks down.

�

Metaphase I

� Homologous pairs line up along the

(11) _______________.

� Spindle fibres attach to the chromosomes.

�

Anaphase I

� The spindle fibres contract. The two members of

each homologous pair separate and move to

(12) _______________ poles of the cell.

� The (13) _______________ starts to divide.

�

Telophase I

� New (14) ______________ _______________ form

around each group of chromosomes.


- 6 -

� Stages of second meiotic division:

Stage Description

�

Prophase II

� The (15) _______________

_______________ breaks down again.

�

Metaphase II

� Chromosomes line up along the equator.

� New (16) _____________ _____________

attach to the chromosomes.

Anaphase II

� The spindle fibres contract. The

(17) _______________ _______________

separate and move to opposite poles of the

cells.

� The cytoplasm starts to divide.

Telophase II

� New nuclear membranes form around each

group of chromosomes.

� The chromosomes uncoil to become

(18) _______________ again.

� Go to

Practical 11.3 Examination of meiotic cell division in a testis squash


Practical 11.4 Examination of meiotic cell division in an anther squash


B What is the importance of meiotic cell division? (Book 2, p. 11-17)

1 Producing haploid gametes

� Meiotic cell division produces haploid gametes for (19) _______________ reproduction

(有性生殖). When the male gamete and the female gamete fuse at fertilization (受精) to form a

zygote (合子), the (20) _______________ number of chromosome can be restored.


- 7 -

2 Producing genetic variations in gametes

� (21) _______________ _______________ (遺傳變異) within a species increase the chance for

the species to survive when environmental conditions change.

� Genetic variations in gametes are produced by (22) _______________ _______________

(獨立分配) of chromosomes and (23) _______________ _______________ (互換).

i) Independent assortment of chromosomes

� In meiosis, pairs of homologous chromosomes line up (24) ______________ along the equator

of the cell. The members of each homologous pair then separate independently of the other

pairs of chromosomes. This is known as independent assortment or (25) _______________

_______________ (隨機分離) of chromosomes.

▲ Independent assortment of chromosomes in meiotic cell division

two possible arrangements of chromosomes at

(26) _______________ _______

parent cell with two pairs of chromosomes

metaphase II

gametes with four

possible genetic

combinations

combination 1 combination 2 combination 3 combination 4

Arrangement 1 Arrangement 2


- 8 -

ii) Crossing over

� Crossing over is an exchange of the corresponding segments of (27) _______________-

_______________ _______________ (非姊妹染色單體) in a pair of homologous chromosomes.

� The process of crossing over:

1 During (28) _______________ _______,

homologous chromosomes pair up.

2 Non-sister chromatids wrap around each other,

forming a (29) _______________ (交叉).

3 At the chiasma, the (30) _______________

break, exchange and rejoin.

chiasma

non-sister chromatids

segments of chromatids exchanged

paternal chromosome

maternal chromosome


- 9 -

11.4 Comparison between mitotic and meiotic cell divisions (Book 2, p. 11-21)

� Similarities:

- (1) _______________ has replicated before the beginning of both processes.

- Both involve nuclear division and (2) _______________ division.

- Both involve the movement of chromosomes and the distribution of chromosomes among

daughter cells.

� Differences: Mitotic cell division Meiotic cell division

Place of occurrence � (3) _______________

cells

� (4) _______________ -

producing cells

Number of cell

division � (5) _______________ � (6) _______________

Pairing of

homologous

chromosomes

� (7) _______________

(Occurs / Does not occur)

� (8) _______________


Separation of

homologous

chromosomes into

daughter nuclei

� (9) _______________


� (10) _______________


Process

Crossing over � Does not occur � May occur

Number produced � (11) _______________ � (12) _______________

Chromosome

number

� Same as parent cell

(diploid / 2n)

� Half of parent cell

(haploid / n)

Genetic make-up � Same as parent cell and

among daughter cells

� Different from parent cell

and among daughter cells

Daughter

cell

Cell type � Body cells � (13) _______________

Importance � Forms genetically

identical cells for growth,

repair and asexual

reproduction

� Forms haploid gametes for

sexual reproduction

� Produces genetic variations

that enhance the survival of

the species


- 10 -

Answers

Ch 11 Cell cycle and division

11.1 1 Cell division 2 parent 3 daughter 4 genetic 5 deoxyribonucleic acid

6 chromosomes 7 chromatin 8 chromatids 9 chromatid 10 chromatin

11 centromere 12 sister chromatids 13 homologous chromosomes 14 paternal chromosome

15 maternal chromosome 16 two 17 diploid 18 one

19 haploid 20 number

11.2 1 mitotic cell division 2 cell cycle 3 Interphase 4 nuclear / cytoplasmic

5 cytoplasmic / nuclear 6 organelles 7 replication 8 two

9 maximum 10 invisible 11 two 12 number / kinds 13 kinds / number

14 mitosis 15 sister chromatids 16 distribution 17 Prophase 18 visible

19 nuclear membrane 20 Metaphase 21 equator 22 Spindle fibres 23 Anaphase

24 contract 25 sister chromatids 26 cytoplasm 27 Telophase 28 nuclear membranes

29 chromatin 30 cytokinesis 31 cytoplasm 32 constricts 33 cell plate

34 cytoplasm 35 identical to 36 asexual

11.3 1 Meiotic cell division 2 gametes 3 half 4 four

5 different from 6 interphase 7 meiosis 8 homologous chromosomes

9 sister chromatids 10 homologous chromosomes 11 equator 12 opposite

13 cytoplasm 14 nuclear membranes 15 nuclear membrane 16 spindle fibres 17 sister chromatids

18 chromatin 19 sexual 20 diploid 21 Genetic variations

22 independent assortment 23 crossing over 24 randomly 25 random segregation

26 metaphase I 27 non-sister chromatids 28 prophase I 29 chiasma

30 chromatids

11.4 1 DNA 2 cytoplasmic 3 Body 4 Gamete 5 One

6 Two 7 Does not occur 8 Occurs 9 Does not occur 10 Occurs

11 Two 12 Four 13 Gametes

class: name: date: 11 cell cycle and divisionbio662.dyndns.info/dse/ws/ws_ch11_e.pdf · new senior...

Documents