Question

Which statement is wrong regarding Photosystem I?

• A. Commonly, it is present in stroma of chloroplast.
• B. It is activated by longer wavelength (above 680nm) of light.
• C. Chlorophyll a to chlorophyll b ratio is less than one.
• D. It is necessary for both cyclic and non-cyclic photophosphorylation.

Hint:

Compare how chlorophyll a and b are distributed between the two photosystems.

Answer 1

The Correct Option is C

Step 1: Go through each statement against known PSI biochemistry. Location in stroma-exposed membrane region, activation by far red light beyond 680 nm at P700, and its dual role in cyclic and non-cyclic electron flow are all textbook facts and hold true.

The pigment composition of PSI is skewed heavily toward chlorophyll a over chlorophyll b, giving a chl a to chl b ratio well above one, not below it.

Since the statement claims the ratio is less than one, it contradicts the real pigment ratio, so it is the false statement. Answer: Chlorophyll a to b ratio is less than one is wrong.