Question

Roots respire through
A) Lenticels
B) Stomata
C) Spiracles
D) None of the above

Answer 1

A plant's roots absorb air from the gaps between sand particles. The air in the sand grains comes into interface with the root hairs. The oxygen in soil particles disperses into root hair and reaches all of the root's cells, where it is used in respiration. By diffusing carbon dioxide generated in root cells throughout respiration, it is expelled by the same root hair.

Complete answer:
Option D None of the above: Roots do not respire through lenticels, stomata or spiracles. They respire through the air spaces found in the soil.
So, Option D is correct.
Option A Lenticels: Lenticels are air-passing apertures on fruits, stems, and tubers that are filled with tenuously connected cells. They do not help in the respiration of roots.
Option A is not correct.
Option B Stomata: Stomata are small holes in the epidermis of leaves, stems, and other vegetative organs. Gases such as carbon dioxide, water vapor, and oxygen can permeate into and out of the plant's interior tissues through stomata. Root does not respire through stomata.
Option B is not correct.
Option C Spiracles: The aperture in the exoskeletons of insects and some spiders that permits air to enter the airways is called a spiracle or stigma. They are not a part of the plant system. Spiracles are not present in roots.
Option C is not correct.

Hence, option D is the correct answer.

Note:
Plant roots normally take in oxygen from miniscule crevices between soil particles and release carbon dioxide. Roots would be unable to produce the energy required to actively take up minerals from the soil if they did not breathe. Farmers dig or tilt the soil to create air holes between the roots for optimum root respiration.