Plant Anatomy and its function

    Plant Anatomy 

Plant anatomy

The study of anatomy is called Plant Anatomy.

Characteristics of root -

* Root hair - It is unicellular. It absorbs water.

* Cuticle and stomata are absent on the outer skin (epidermis).

* Casparian strip is present in endodermis.

* Vascular bundle is radial.

* Xylem is exarch.


Exarch - is present between protoxylem edge and metaxylem. Diameter of protoxylem is small and diameter of metaxylem is large.


What are the characteristics of stem?


* Cellular hairs are found on it.

* A structure called hypodermis is present on it.

* Casperian stripe is not found on its endodermis.

* Vascular bundles are conjoint and collateral on it. * Xylem endarch is found in the middle of protoxylem and at the edge of metaxylem.


Plant Anatomy
 
Stem of Dicotyledonous Plant -

* Vascular bundle is found inside a ring like structure.

* Phloem is present in Parenchyma.

* Hypodermis is Collenchyma.

* Secondary growth is found in it.

Stem of Monocotyledonous Plant -

* Vascular Bundle Xylem & Phloem are scattered.

* Hypodermis is Sclerenchymatous.

* Phloem Parenchyma and secondary growth are also not found in it.

Characteristics of Leaf -

Dicotyledonous Leaf - Stomata is found only on lower surface.

* Mesophyll Tissue which is found in leaves, has Palisade in its upper part and Spongy tissue in its lower part.

* Photosynthesis usually takes place on the upper part of the leaf.

* Vascular bundle is large in the middle but small at the edges.

* Leaves are dorsiventral dorsal-ventral.

Monocotyledonous leaf - Stomata are found on both the upper and lower surfaces.

* In this Mesophyll tissue is not divided.

* In this photosynthesis takes place equally on both the surfaces of the leaf.

* In this vascular bundle is of similar shape.

What is secondary growth in stem?

When the thickness of the plant increases then it is called secondary growth. Generally secondary growth does not take place in monocotyledonous plant. And this is the reason that Cambium tissue is not found in it. When the thickness of the stem increases in the plant then it is called Intrastellar Growth. And if the circumference of the plant increases then it is called Extrastellar Growth.

* When Cambium ring divides then it forms Secondary Phloem and Secondary Xylem. * Wood          means Secondary Xylem
* Large Xylem cavities are formed in spring season.

* Small Xylem cavities are formed in autumn season.

* Younger Secondary Xylem transports fluid in the plant, which is called Sap Wood.

* The phenomenon of closing of Xylem Cavities is called Tylosis.

* Wood containing Cavity Tanin is called heart wood.








                                                                                                                     Dr. Prashant Singh
                                                                                                                            Phd (Psy)




























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