1. meristem
TRANSCRIPT
-
8/3/2019 1. Meristem
1/16
Tissue is a cellular
organizational level
intermediate
between cells and a
complete organism.
Tissues togethercarry out a specific
function.
Chapter 4. Tissue
http://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_(biology) -
8/3/2019 1. Meristem
2/16
a) Apical Meristem: It is present at thegrowing tips of stems and roots and
increases the length of the stem and root.
4.2.1. Meristem
Classification of meristematic Tissue
b) Lateral Meristem: This meristemconsist of cells which mainly divide in oneplane and cause the organ to increase in
diameter and growth.
c) Intercalary Meristem: This meristemis located in between permanent tissues.It is usually present at the base of node,
inter node and on leaf base.
A meristem is the tissue in all plants consisting of undifferentiated cells(meristematic cells), found in zones of the plant where growth can take place.
http://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristem -
8/3/2019 1. Meristem
3/16
-
8/3/2019 1. Meristem
4/16
Shoot apical meristem (SAM)
Central zone (CZ)undifferentiated cells
Peripheral zone (PZ)formation of newlateral organsRib zone (RZ)formation of new stem
Layer 1 (L1)Generates
epidermisLayer 2 (L2)Layer 3 (L3)Generateinternal tissue
L1 + L2: anticlinal cell divisionsL3: randomly oriented cell divisions
-
8/3/2019 1. Meristem
5/16
(a) Shoot apical meristem, (b) Leaf primordial,(c) Axillary bud primordium, (d) leaf, (e) Stem tissue
-
8/3/2019 1. Meristem
6/16
Root apical meristem (RAM) - Root development
Root tip has four developmental zones:Root cap
Meristematic zoneElongation zoneMaturation (Differentiation) zone
RAM contains several types of stem cellsAll root tissues are derived from a small
number of stem cells in RAM
-
8/3/2019 1. Meristem
7/16
-
8/3/2019 1. Meristem
8/16
Lateral meristem
It is a secondarymeristem whichoccupies lateralposition e.g.Cambium, Corkcambium (Conifer,Dicot). It is responsible
for increases in girth.
-
8/3/2019 1. Meristem
9/16
-
8/3/2019 1. Meristem
10/16
http://www.uic.edu/classes/bios/bios100/labs/meristem.jpg -
8/3/2019 1. Meristem
11/16
Intercalary meristem ismeristem at the base of theinternode in monocot stems(particularly grass stems).
Only the apical meristem isactive. If the tip of the stem isremoved, the uppermostintact intercalary meristem
becomes the apical meristemand starts intercalary growth.
Intercalary meristem
http://www.puc.edu/Faculty/Gilbert_Muth/botglosm.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosi.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosm.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosa.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosi.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosi.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosa.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosa.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosm.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosi.htmhttp://www.puc.edu/Faculty/Gilbert_Muth/botglosm.htm -
8/3/2019 1. Meristem
12/16
It is the meristem that
occurs betweenpermanent tissues. Itrepresents the remnant of
the apical meristem. It isparticularly common atthe nodal regions. It mayalso occur at the base of
the leaves.
-
8/3/2019 1. Meristem
13/16
-
8/3/2019 1. Meristem
14/16
SUMMARY
-
8/3/2019 1. Meristem
15/16
a) Apical Meristem: It is present at the growing tips of stems and rootsand increases the length of the stem and root. They form growing parts atthe apices of roots and stems and are responsible for increase in length,also called primary growth. This meristem is responsible for the lineargrowth of an organ.
4.2.1. Meristem
b) Lateral Meristem: This meristem consist of cells which mainly dividein one plane and cause the organ to increase in diameter and growth.Lateral Meristem usually occurs beneath the bark of the tree in the formof Cork Cambium and in vascular bundles of dicots in the form of
vascular cambium. The activity of this cambium results in the formation ofsecondary growth.
c) Intercalary Meristem: This meristem is located in between permanenttissues. It is usually present at the base of node, inter node and on leafbase. They are responsible for growth in length of the plant. This adds
growth in the girth of stem.
Classification of meristematic Tissue
http://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Vascular_cambiumhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Vascular_cambiumhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristemhttp://en.wikipedia.org/wiki/Meristem -
8/3/2019 1. Meristem
16/16
Ground tissue: Ground tissue is less differentiated than
other tissues. Ground tissue manufactures nutrients by
photosynthesis and stores reserve nutrients.
Epidermis: Cells forming the
outer surface of the leaves
and of the young plant body.
Vascular tissue: The primarycomponents of vascular
tissue are the xylem and
phloem. These transport fluid
and nutrients internally.
Classification of Tissue
http://en.wikipedia.org/wiki/Ground_tissuehttp://en.wikipedia.org/wiki/Epidermis_(botany)http://en.wikipedia.org/wiki/Vascular_tissuehttp://en.wikipedia.org/wiki/Vascular_tissuehttp://en.wikipedia.org/wiki/Epidermis_(botany)http://en.wikipedia.org/wiki/Ground_tissue