AP BIOLOGY

PHOTOSYNTHESIS

LIGHT DEPENDENT REACTIONS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
In which type of environment are plants most likely to use a C4 pathway of carbon fixation?
A
cold and wet
B
cold and dry
C
hot and wet
D
hot and dry
Explanation: 

Detailed explanation-1: -Answer. Hot & Dry conditions.. Because C4 cycle is used in reducing the loss of water during hot seasons.

Detailed explanation-2: -Most C4 plants are native to the tropics and warm temperate zones with high light intensity and high temperature. Under these conditions, C4 plants exhibit higher photosynthetic and growth rates due to gains in the water, carbon and nitrogen efficiency uses.

Detailed explanation-3: -C4 plants are generally found in hot, dry environments where conditions favor the wasteful photorespiration reactions of RUBISCO, as well as loss of water.

Detailed explanation-4: -They evolved in cold weather but migrated to the tropics, where they were more suitable. They suspend photosynthesis in the heat. The same cells that bind carbon dioxide perform the Calvin cycle. Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low.

Detailed explanation-5: -C4 photosynthesis is an adaptation for plants living in hot, arid climates. Some plants that live in hot, dry climates maintain low oxygen levels in their leaves by keeping the stomata closed to prevent water loss.

There is 1 question to complete.