Question

Leaves of annual plant obtain $O_2$ through
A) Cell Walls
B) Cuticle and leaf scars
C) Stomata
D) Lenticels

Answer 1

Hint:Annual plants are the plants which complete their entire life cycle in a single growing season. The life cycle involves growing of vegetative parts, blooming, producing seeds and then dying. Examples are carrot, celery etc. The annual plants are mostly herb or shrubs.

Complete answer:
To answer this question, we must know about the gaseous exchange in plants.
The gaseous exchange is an important phenomenon in plants. Plants absorb carbon dioxide and water vapour and release oxygen. This gaseous exchange in plants is very useful for photosynthesis and respiration.

The gaseous exchange in the plants takes place through the fine opening present on the lower surface of the leaf called the stomata. This opening is regulated by the guard cell. The stomata pores are open during the day and closed during the night.

-Cell walls- It is the outermost layer of the plant cell which protects the plant from mechanical stress.
-Cuticle and leaf scar- Cuticle is the wax layer present over the leaf. It prevents transpiration. Leaf scar is the mark left by the leaf after it falls.
-Lenticels- It is the pore or opening in the woody stem through which gaseous exchange takes place. It is absent in annual plants.

Thus the correct answer is (C). Leaves of the annual plant obtain $O_2$ through stomata.

Note:Lenticels are the porous tissues found on the woody stem, root or trunk of trees. Its main function is respiration. Lenticels are also found in the skin of fruits like apple, pears.