Anatomy of Flowering Plants

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b. Intercalary meristems

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They occur between mature tissues. They occur in grasses and

regenerate parts removed by the grazing herbivores (Odisha NEET 2019).

Apical and intercalary meristems are primary meristems because they

appear early in a plant life and contribute to the formation of primary

plant body. During that, specific regions of the apical meristem produce

dermal tissues, ground tissues and vascular tissues.

(2) Secondary (lateral) meristems: The meristems that occur in mature

regions of roots and shoots . It produces woody axis and appear later

than primary meristem. They are cylindrical meristems. They are seen

in gymnosperms and dicots. E.g. Fascicular vascular cambium, inter

fascicular cambium & cork cambium. These are responsible for

producing the secondary tissues.

PËRMÅÑËÑT (MÅTÜRË) TÏSSÜËS

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The cells produced by primary and secondary meristems, become

structurally and functionally specialized and lose the ability to divide.

They are called permanent (mature) cells and constitute the permanent

tissues.

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They are of 2 types: Simple and Complex.

1. Simple Permanent Tissues

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The tissues having all cells similar in structure & function.

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3 types: Parenchyma, Collenchyma and Sclerenchyma.

Potato

Cross section

Longitudinal

Longitud

Cross sect

Intracellular

airspace

Thin primary

cell wall

Nucleus

Cytoplasm

Starch grain

Vacuole

Cel

a. Parenchyma

It forms the major component

within organs.

Cells are generally isodiametric.

They may be spherical, oval,

round, polygonal or elongated.

Their walls are thin and made

up of cellulose.

Cells are closely packed or have

small intercellular spaces.

Functions:

Photosynthesis,

storage, secretion etc.