Question

Phytochrome absorbs visible light maximum in red region at

• A. $600nm$
• B. $650nm$
• C. $660nm$
• D. $730nm$

Answer 1

The correct option is C $660nm$

Phytochrome are plant pigment which are involved in various plant responses. There are two forms of phytochrome, the inactive form P${}_r$ and the active form P${}_{fr}$. P${}_r$ absorbs red light strongly. The absorbance maximum is at 660 nm. P${}_{fr}$ absorbs far-red light strongly. The absorbance maximum is at 730 nm.

Thus, the correct answer is option C.