General Science question from Laboratory Attendant exam, 2026 by JKSSB
Which plant structures function as gateways for gas exchange?
Last updated Jun 18, 2026
Correct Answer:
Option B —
Stomata
(Note: Depending on the context of your test, B) Stomata is often considered the primary answer for leaves, but scientifically both Stomata and Lenticels act as gateways for gas exchange in plants).
Here is a breakdown of how these structures function as gateways, along with why the other options are incorrect:
Gas Exchange Gateways
B) Stomata: These are microscopic pores found primarily on the epidermis of leaves and green stems. They are surrounded by guard cells that open and close to regulate the exchange of carbon dioxide and oxygen, as well as water vapor during transpiration.
A) Lenticels: These are porous tissues found on the bark of woody stems and roots of mature plants. Because woody bark is impermeable to gases, lenticels provide a pathway for the internal tissues to exchange gases with the surrounding atmosphere.
Transport Tissues (Incorrect Options)
C) Xylem: This is a vascular tissue responsible for transporting water and dissolved minerals upwards from the roots to the leaves. It does not handle gas exchange.
D) Phloem: This is a vascular tissue responsible for transporting soluble organic compounds (like sucrose/food made during photosynthesis) from the leaves to the rest of the plant. It also does not function as a gas exchange gateway.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
