Morphology of Plants Flashcards
Root System?
The main branches and its lateral branches form the root system.
Roots are
Positively Geotropic & Negatively Phototropic.
Tap Root system is present in
Dicots.
Fibrous root system is present in,
Monocots.
Adventitious root system:
these develop from any parts of plant except radicle, e.g. Grass, Monstera, Banyan Tree.
Functions of root:
1) Absorption of water and minerals.
2) Provide anchorage to plant parts.
3) Storage of reserve food material.
4) Synthesis of plant growth regulators.
Regions of the Root?
i) Root Cap
ii) Region of meristematic activity
iii) Region of elongation
iv) Region of maturation.
Root Cap:
The apex of the root is covered by thimble like str. cld Root Cap, Multicellular. Formed of Parenchymatous Cells, Protects the tender apex.
Region of meristematic activity :?
Few mms above root cap, Cells are thin-walled, small, dense cytoplasm, Divide repeatedly to form new cells.
Region of elongation ?
proximal to meristematic region, undergo rapid elongation and enlargement & are responsible for growth of roots in length.
Region of maturation. ?
Cell Elongation zone gradually differentiates and mature. This is proximal to region of elongation.
Root Hair?
some epidermal cells from the region of maturation form very fine and delicate thread like structures called root hair.
Function of Root Hair?
Increase the surface area for absorption of water and minerals from the soil.
Storage Roots
Primary tap root is modified to store food and assumes various shapes.
Examples of Storage Roots
Tap root of Carrot, turnip, radish, beet and adventitious roots of sweet potato get swollen and store food.
Respiratory Roots
in swampy areas many roots come out of the ground vertically upwards to get oxygen for respiration. Called Pneumatophores.
Pneumatophores present in:
Rhizophora, Maangrove
Prop roots:
arise from branches of stem for providing mechanical support to heavy branches, e.g. Banyan Tree.
Banyan Tree scientific name
Ficus benghalensis
Stilt roots: ?
arise from lower nodes of stem to support main axis and enter soil obliquely, e.g. Sugarcane, Maize.
What gives rise to the stem?
The plumule of the embryo present in the germinating seed gives rise to the stem.
The region bearing leaves, present at regular intervals on the stem and its branches are called
Nodes
Part of stem present bw two nodes:
Internode.
A bud:
Young, Immature, under developed, compact shoot.
i) Terminal Bud
ii) Axillary Bud