Question

The substances which have proved very effective in inducing root from the cut end of the stem is-
A. Phenylacetic acid
B. $\alpha -$ naphthalene acetic acid
C. Indole acetic acid
D. Indole butyric acid

Answer 1

Hint: Roots are also a propagation medium which is practiced by root cutting so it will develop into a whole new plant. All the tuber plants possess this quality to maintain their hereditary line. Some examples of crops are- strawberries, rose, hibiscus. It can be economically beneficial and commercially too. It is also cost effective and takes less time to reproduce.

Complete answer:
Option A: Phenylacetic acid- phenylacetic acid is an organic compound used to treat hyper ammonia in adult people. It is being used as a treatment for human beings, not plants.
Option A is not the correct answer.
Option B: $\alpha -$ naphthalene acetic acid- naphthalene are also chemical compounds used as a disinfectant in killing microbes and also controlling foul smell.
Option B is not the correct answer.
Option C: Indole acetic acid- Indole acetic acid or IAA is one of the known plant hormones. Used for strengthening roots and shoot systems.
Option C is not the correct answer.
Option D: Indole butyric acid- Indole butyric hormone is the hormone which helps in inducing roots from the cut of the stem.
Option D is the correct answer.

Hence, Option D is the correct answer.

Note:
Root cutting is a type of artificial method. Horticulturalists techniques are being used to culture it or produce it artificially. This uses the vegetative parts to replicate plants. Root cutting from stem ends is a type of vegetative propagation. Chemical compound or hormone is butyric acid. Plants have their own hormones just like animals produce hormones.