Question

Roots developing from plant parts other than radical are
A) Epiphyllous
B) Epicaulous
C) Adventitious
D) Fibrous

Answer 1

The descending part of the plant, which grows under the soil is the root. The roots that arise from any part of the plant other than the radicle or its branches are called adventitious roots. They generally reproduce from stem nodes, internodes, leaves, etc.

Complete answer: During germination, the radicle from the seed grows downward and branches out. The branches jointly with the primary root are called the root system. Roots lack chlorophyll and hence they are not green in color. Roots are positively geotropic and hydrotropic, that is, they grow towards the ground and water and negatively phototropic, which is growing away from. light. There are three types of root systems found in plants. such as,
1. Taproot System
Dicots mainly have this type of root system, where the primary root grows from the radicle of the germinating seeds. Other roots sprout laterally from the primary root in this kind of root system. The Taproot system provides the plant a very good anchorage and the taproot grows deep into the soil. Examples- Mango, Mustard, Gram, Etc.
2. The Fibrous Root System
The fibrous root system is shown by monocots where the roots develop into a thin and dense network. These types of roots do not penetrate deeper into the soil. They remain close to the surface. Hence, they cannot provide strong anchorage like Taproots. The branching roots may also grow from a primary root in some plants, but the primary root is short-lived. The roots arise from the radicle and plumule of the growing plant with this type of root system. Some plants may also have a combination of taproots and fibrous roots. Examples- Wheat, Paddy, Onion, Maize, Etc.
3. The Adventitious Root System
Adventitious roots arise from the plant parts other than the radicle of the plant. Monocots mostly have the adventitious root system. Roots arise from stems, leaves, shoots, or any other plant part in this case. Adventitious roots develop normally or under conditions of stress. They are rather a part developed to sustain extreme conditions. The conditions of stress might be drought, absence of nutrients, or physical wounds. Adventitious roots provide vegetatively propagation, support, etc. Examples-Banyan Tree, Maize, Oak Tree, Black pepper tree, beetle tree, etc.
Adventitious roots are modified for a variety of functions such as storage of food, mechanical support, etc. from their typical functions. Some modifications of adventitious roots are listed as:
a) Storage of Food: Annulated root, Nodulose root, Tuberous root, Fasciculated root, Moniliform root Tuberous roots: Tuberous roots are fleshy, do not have any particular shape, and often get swollen. Example- Sweet Potato (Ipomoea batatas).
b) Moniliform roots: These roots are also inflated at regular intervals which renders a beautiful appearance to the roots. Example-Rose moss (Portulaca grandiflora).
c) Annulated roots: In this root, a series of outgrowths, which resemble the shape of rings, are present on the body. Example-Ipecac (Cephaelis ipecacuanha).
Mechanical Strength:
1. Prop or Pillar Adventitious Roots: These roots grow downward from the branches of the trees and are adjusted to promote the thick and heavy branches. The aerial roots are hygroscopic. Example- Banyan Tree (Ficus benghalensis).
2. Climbing Roots: These roots are found in climbers. They are non-absorptive roots that help the plant to anchor to the structure. Example: Tecoma (<Tecoma stans).
3. Buttress Roots: These roots develop at the base of the stem and help in maintaining the structural integrity of the plant. The basal part of the stem is vertically elongated and spreads in different directions in the soil. Example: Arjuna Tree (Terminalia arjuna).
4. Vital functions: In plants like Trapa, some roots are green in color and are capable of photosynthesis, and are known as assimilation roots. In some plants, the roots occur in parasites for absorbing nourishment from the host is known as sucking roots.
Thus, the answer is option C: Adventitious.

Note: In the Banyan tree, even if the trunk dies, the tree as a whole remains alive because the prop roots of the tree are supporting and nourishing the crown. The largest tree specimen of Banyan in the Guinness Book of World Records is found in Thimmamma Merriman village of Anantapur district in Andhra Pradesh, India.