NEET BIOLOGY

Detailed explanation-1: -Gravitropism directs roots to grow downward at germination, the growth mechanism of plants that also causes the shoot to grow upward.

Detailed explanation-2: -Explanation : Roots – Roots grow down because the root respond to gravity by releasing the chemicals that prevent growth on the lower side, thus turning the root downwards.

Detailed explanation-3: -Roots grow where water, minerals and oxygen are found in the soil and allow root growth. Roots need some water and oxygen but if soils are saturated with water, most roots will die. Because oxygen is usually located in the upper surface layer of soil, the largest concentration of feeder roots exists in this zone.

Detailed explanation-4: -Geotropism (also called gravitropism) is the directional growth of an organism in response to gravity. Roots display positive geotropism when they grow downward, while shoots display negative geotropism when they grow upward.

Detailed explanation-5: -Roots grow in length only from their ends. The very tip of the root is covered by a thimble-shaped root cap, which serves to protect the growing tip as it makes its way through the soil. Just behind the root cap lies the apical meristem, a tissue of actively dividing cells.