1
Question
The CAM photosynthetic pathway is preferred by desert plants because
The CAM photosynthetic pathway is preferred by desert plants because
Open in App
Solution
The correct option is B it allows the stomata to be closed during the day
Desert plants or xerophytic plants are adapted to hot and dry climates. E.g., Opuntia
Transpiration (loss of water in the form of water vapour) occurs, majorly, through the tiny pores on the leaves of a plant called stomata. As stomata remain open during the day time, in most plants stomatal transpiration occurs during the day.
The rate of transpiration increases with increase in temperature and decrease in humid environments (presence of water vapour in the atmosphere). Thus in hot and dry conditions of a desert, the rate of transpiration is very high. This excessive loss of water can dehydrate the plant cells and turn them flaccid, causing the plant to wilt and eventually die.
Desert plants have special morphological and physiological adaptations or mechanisms that allow them to conserve water and prevent water loss by transpiration from aerial parts of a plant. This include :
- Sunken (buried in pits) stomata
- Leafs modified to spines
- Thick cuticle
Figure : Sunken stomata
The stomata in most xerophytic plants remain closed during the day to prevent transpiration. This can interfere with the plant’s photosynthetic ability as plants take carbon dioxide, needed for photosynthesis, via the stomatal pores. As a result, these plants follow a specialised photosynthetic pathway known as the Crassulacean acid metabolism (CAM) pathway that allows the stomata to be closed during the day, without hampering the process of photosynthesis.
Figure : CAM cycle
Therefore, with the help of CAM cycle desert plants are able to prevent water loss by closing stomata during the daytime and still able to carry out photosynthesis. Thus, option b is the correct answer.
For carrying out photosynthesis the ingredients like water and carbon dioxide are required. Energy (ATP and NADPH) is required to fix carbon dioxide in the form of glucose in photosyntheis. Hence option a, c and d are incorrect.
Desert plants or xerophytic plants are adapted to hot and dry climates. E.g., Opuntia
Transpiration (loss of water in the form of water vapour) occurs, majorly, through the tiny pores on the leaves of a plant called stomata. As stomata remain open during the day time, in most plants stomatal transpiration occurs during the day.
The rate of transpiration increases with increase in temperature and decrease in humid environments (presence of water vapour in the atmosphere). Thus in hot and dry conditions of a desert, the rate of transpiration is very high. This excessive loss of water can dehydrate the plant cells and turn them flaccid, causing the plant to wilt and eventually die.
Desert plants have special morphological and physiological adaptations or mechanisms that allow them to conserve water and prevent water loss by transpiration from aerial parts of a plant. This include :
- Sunken (buried in pits) stomata
- Leafs modified to spines
- Thick cuticle
Figure : Sunken stomataThe stomata in most xerophytic plants remain closed during the day to prevent transpiration. This can interfere with the plant’s photosynthetic ability as plants take carbon dioxide, needed for photosynthesis, via the stomatal pores. As a result, these plants follow a specialised photosynthetic pathway known as the Crassulacean acid metabolism (CAM) pathway that allows the stomata to be closed during the day, without hampering the process of photosynthesis.
Figure : CAM cycleTherefore, with the help of CAM cycle desert plants are able to prevent water loss by closing stomata during the daytime and still able to carry out photosynthesis. Thus, option b is the correct answer.
For carrying out photosynthesis the ingredients like water and carbon dioxide are required. Energy (ATP and NADPH) is required to fix carbon dioxide in the form of glucose in photosyntheis. Hence option a, c and d are incorrect.
Suggest Corrections
0
Similar questions