Question

The C4 photosynthetic pathway is most common in

A) gymnosperm trees.
B) angiosperm trees.
C) algae, bryophytes, and ferns.
D) grasses and shrubs in warm and dry climates.

Answer 1

The C4 photosynthetic pathway is most common in grasses and shrubs found in warm and dry climates, where it helps to minimize water loss while fixing CO2 efficiently.

Step-by-step explanation:

The C4 photosynthetic pathway is commonly found in grasses and shrubs in warm and dry climates (option D). The C4 pathway is an adaptation that allows plants to efficiently fix carbon dioxide while minimizing water loss. This pathway is different from the C3 pathway found in temperate species and the CAM pathway in plants like cacti that fix carbon dioxide at night. C4 plants, like corn, utilize an enzyme called PEP carboxylase to initially fix carbon dioxide into a four-carbon compound in the mesophyll cells. This compound is then transported to bundle sheath cells where the carbon dioxide is released and then fixed again by rubisco, allowing for a more concentrated carbon dioxide environment, reducing photorespiration and increasing water-use efficiency in hot and dry environments.