Morphology of Flowering Plants: Root System in Plants II Free Notes II LetsBloomStudyMaterial II For PGT Biology exams with Previous year questions

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PARTS OF EMBRYO: 

  • A seed comprises of an Embryo and Cotyledon.
  • An Embryo comprises of Radicle, Plumule and Hypocotyl.
  • Plumule is the Embryonic stem.
  • Radicle is the Embryonic root.

Plant Root System:

There are two types of Root System on the basis of their morphology and development:

1. FIBROUS Roots

2. TAP roots.

In Tap root there is a main primary root from where lateral roots arises.

In Fibrous root system several main roots form a bunch.

Basics of Root development:

  • Upon seed germination Radicle forms embryonic root that further form main primary root of the plant called as Tap Root.
  • EXAMPLES: Most of Dicot Plants.
But in Monocots there were several roots but only one radicle so how roots develop?
  • In Monocots several roots arise just above radicle called as Fibrous Roots.
  • In Monocots primary root is short lived and replaced by large number of roots
  • Another type of roots are Adventitious roots:
  • Roots that develop from leaves and Stem are called as Adventitious roots
  • Prop Roots: The roots developed at lowest node of plant is Prop Roots.
  • EXAMPLES: Wheat (Triticum vulgare) Maize (Zea mays) Sugarcane (Saccharum officinale) etc.
  • Their main function is to provide additional support to the plant.
  • Aerial Roots: Roots that extend down from aerial branches into the soil are called as Aerial roots. 
  • EXAMPLES: Ficus benghalensis, Philodendron etc.
  • Pneumatophores: Roots arises from mud in swampy/Marshy area plants are called as Pneumatophores. The have lenticels that absorb oxygen from environment.
  • EXAMPLES: Mangrove trees Rhizophora mangle etc.
  • Roots from Leaves: Begonia, Bryophyllum etc.


Modification of Roots

Tap roots may get modified to store food for Example:

Carrot (Dacus caryota)

Radish (Raphanus sativus)

Turnip (Brassica rapa)

Beet (Beta vulgaris)

Adventitious root may also get modified to store food for Example: Sweet Potato (Ipomoea batata), Amaranthus 

PREVIOUS YEAR QUESTIONS:

1.The Collateral and Open type of Vascular bundle with Endarch Xylem are found usually in:

  • Monocot Stem
  • Dicot Stem
  • Monocot Root
  • Dicot Root

2. The region of stem from where leaves are borne is called

  • Node
  • Internodes
  • Bud
  • Gemmule

3. Consider the following:

This part of plant bear both node and internode.

It is generally green when young and changes colour later.

Which of the following parts has been described?

  • Root
  • Stem
  • Leaves
  • Bud
4.What is the Function of Prop Roots?
  • Get oxygen for plant
  • Provide extra support to plant
  • Storage of food
  • Storage of food and water
5. Which of the following does not have stilt roots?
                                               
  • Saccharum officinale
  • Zea mays
  • Triticum vulgare 
  • Ficus benghalensis    
6. Which of the following is incorrect modification
  • Carrot-Modified Root
  • Garlic-Modified Flower
  • Colocasia-Modified Stem
  • Onion-Modified leaves
Garlic is modified stem.

7. Which plant is growing in swampy areas with many roots coming out of ground and growing vertically upward?
  • Mirabilis
  • Rhizophora
  • Banyan Tree
  • Monstera
8. In which of the following primary root is short lived and replaced by large number of roots. These roots originate from base of stem and constitute the fibrous root system
  • Gymnosperms
  • Monocotyledons
  • Dicotyledons
  • Bryophyta
9. We can eat the roots of many plants. Which of the following is the example of a plant with edible roots?
  • Wheat
  • Potato
  • Mango
  • Sweet potato
EXPLANTION: 
Sweet potato is Modified root
Mango is Modified Flower
Potato is Modified Stem.
Wheat is inflorescence.

10. Distal part of apical meristem of root is
  • Lateral in Position
  • Sublateral in Position
  • Terminal in Position
  • Sub terminal in Position
EXPLANTION: 
The distal part of apical meristem of rot is called as Root cap just beyond it is Root Apical Meristem. 

11. The vegetation having Pneumatophores, Prop roots, Viviparous type of root germination and stem with thick cuticle are characteristic of?
  • Xerophytes
  • Mangroves
  • Succulent Xerophytes
  • Epiphytes
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