Biology TRUE / FALSE

True
Reason: During the day, the stomata are open to facilitate the inward diffusion of carbon dioxide for photosynthesis. During mid-day, the outside temperature is higher, due to which there is more evaporation of water from the leaves. Therefore more transpiration occurs during mid-day.

True
Reason: Desert plants need to reduce transpiration as much as possible so as to survive in the hot and dry environment. Hence some of them have sunken stomata as an adaptation to curtail transpiration.

False
Reason: Transpiration is reduced during high atmospheric humidity. High humidity in the air reduces the rate of outward diffusion of the internal water vapour across stomata, thereby reducing the rate of transpiration

False
Reason: Hydathodes are special pores present on the ends of leaf veins through which guttation occurs and water droplets are given out. Their openings cannot be regulated. Stomata on the other hand are minute openings in the epidermal layer of leaves through which exchange of gases as well as transpiration occurs. Water is given out as water vapour. Stomatal opening is regulated by guard cells.

False
Reason : Potometer is used to measure the rate of transpiration in a plant. Demonstration of transpiration occurring from the lower surface of a leaf is done by analyzing the changes in colour of pieces of dry cobalt chloride paper attached (and held in place) to the two surfaces of a leaf.

(a) False
(b) Potometer is an instrument used for measuring the rate of transpiration in green plants.

(a) False
(b) Most transpiration occurs at mid-day.

true

FALSE, guttation occurs through hydathodes.

true

FALSE, a controlled experiment is one in which two identical experiments are set up.

FALSE, moist cobalt chloride paper is pink in colour.

FALSE, cobalt chloride paper is used to demonstrate transpiration.

FALSE, high humidity in the atmosphere results in decrease in the rate of transpiration.

FALSE, the wall of the guard cells towards the stoma is thick.

FALSE, evaporation is a physical process.

true

FALSE, more transpiration occurs from the lower surface of a leaf.

true