Photosynthesis In Higher Plants Question 95
Question: Assertion : There is a decrease in photosynthesis, if the photosynthetic cells are illuminated by light of $ P_{680} $ nm or more wavelength. Reason : In red drop phenomenon the rate of photosynthesis decreases.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: B
Solution:
Although the efficiency of photosynthesis is uniform over most of the spectrum, it declines significantly in the red, i.e., at wavelength of 680 nm and above.
This phenomenon is called red drop.
However, it was shown by Emerson that if light at 680 nm is supplemented with light of a shorter wavelength (< 600 nm), the quantum efficiency of photosynthesis in the red can be restored to normal.
BETA
