Plants have organs which are composed of different tissues, which in
turn are composed of cells of different types. A tissue is a group of cells
with a common function, structure or both. An organ consists of several types
of tissues that together carry out particular function.
DIFFERENT PLANT CELLS
A flowering plant has the ability to grow its entire life because it
possesses meristermatic (embryonic) tissues. The apical meristems are located at
or near the tips of stem and roots, where they increase the length of their
structure by means of mitosis. This increase in length is called primary growth.
Monocots also have an intercalary meristem; this allows them to
regrow lost parts.
The apical meristem produces three types of meristems and these are
develop into the three types of specialized primary tissues in the body of the
plant:
· Protoderm
gives rise to the epidermis
· Ground
meristem gives rise to ground tissue
· Procambrium
gives rise to vascular tissue
STRUCTURE AND FUNCTION OF SPECIALIZED PLANT TISSUES OF EPIDERMIS
EPIDERMIS
A. EPIDERMAL TISSUE
EXAMPLE OF AN EPIDERMAL TISSUE
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STRUCTURE
It is a single layer of closely packed, flat, brick shaped cells with a
large vacuole. Then Ariel parts of the plant are covered with a cuticle.
FUNCTION
The cuticle minimizes water loss (because it has cutin) and protects the
plant against bacteria
B. ROOT HAIRS
EXAMPLE OF A ROOT HAIR
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STRUCTURE
They are specialized epidermal cells of the roots. Unicellular outgrowth
of the epidermal cell.
FUCTION
Increase the surface area of the root for absorption of water and
minerals. it also anchor the plant.
C.TRICHOMES (STERM AND LEAVES HAIR)
TRICHOMES
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STRUCTURE
It is a specialized epidermal cell of stems and leaves. Multicellular
outgrowth of the stem and leaves.
FUNCTION
Protects the plant from sun and conserve moisture. Protects plants and
from herbivores, produce toxic substances.
D. STOMATA
stomata
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STRUCTURE
Specialized epidermal cells called guard cells, which are bean shaped,
enclosed an opening called a stoma pore. The guard cells contain a nucleus and
chloroplast. It has a thick inner membrane. Woody plants have lenticels.
FUNCTION
Transpiration and gaseous exchange take place through the stomata
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