NEET Botany - MCQ Practice Questions

In C3 plants, the enzyme RuBisCO catalyzes carboxylation. Under what condition does RuBisCO exhibit oxygenase activity instead?

In the light-dependent reactions, non-cyclic photophosphorylation produces ATP and NADPH in a ratio of approximately:

A seedling grown under continuous red light shows etiolation symptoms. This is primarily because:

The quantum requirement for photosynthesis (minimum number of photons needed to fix one CO2) is approximately:

A plant exhibits wilting despite adequate soil moisture. The most likely explanation involves:

Under conditions of high light intensity and stomatal closure, what is the primary fate of electrons in the thylakoid?

In photorespiration, glycolate (2-phosphoglycolate) is initially oxidized in peroxisomes. This process consumes O2 but generates no ATP. What is the primary consequence?

A plant grown under continuous red light shows reduced stem elongation compared to white light. Which photoreceptor is primarily responsible for this response?

In C4 plants, the first stable product of photosynthesis is oxaloacetate (4-carbon compound). Which of the following is the primary advantage of this mechanism in tropical environments?

During seed germination, reserve mobilization occurs through enzyme activation. Which hormone primarily promotes the synthesis of α-amylase in the aleurone layer of cereal grains?