AP BIOLOGY

Detailed explanation-1: -The rate of transpiration increases when atmospheric pressure is low. During low atmospheric pressure, air will move out of the plant as a result of diffusion. At low pressure, the water vapour moves fast thus the rate of transpiration increases.

Detailed explanation-2: -Transpiration is the evaporation of water from plants. It occurs chiefly at the leaves while their stomata are open for the passage of CO2 and O2 during photosynthesis.

Detailed explanation-3: -The rate of transpiration will increase with a decrease in atmospheric pressure. Air will move out of the plant easily as the atmospheric pressure decreases. Hence, the rate of transpiration increases, and plants lose more water easily. So, option B is the correct option.

Detailed explanation-4: -Plants transpire more rapidly in the light than in the dark. This is largely because light stimulates the opening of the stomata (a mechanism). Light also speeds up transpiration by warming the leaf. Plants transpire more rapidly at higher temperatures because water evaporates more rapidly as the temperature rises.

Detailed explanation-5: -At higher relative humidity, there is less transpiration. Carbon dioxide levels in the air that control the stomata opening will also influence transpiration rates. In addition, various biochemical and morphological features of plants will also affect transpiration rate: Orientation of leaves.