Answer:
E
Explanation:
Phytochrome is an important pigment that regulates photomorphogenic aspects of plant growth and development such as seed germination, stem elongation, leaf expansion, formation of certain pigments, chloroplast development and flowering.
Phytochrome has two different chemical structures that are inter-convertible. The forms are named by the color of light they absorb maximally: Pr is a blue form that absorbs red light strongly (660nm) and Pfr is a blue-collar form that absorbs far-red light strongly (730nm). When each phytochrome form absorbs its respective photon, they change chemically into their complementary form.
N.B: In plants, Pfr is the physiologically active or signalling state.
In the dark, phytochrome is in the Pr (inactive) form because at night, Pfr slowly converts back to Pr (inactive form).
The biologically inactive form of phytochrome (Pr) is converted to the biologically active form (Pfr) under illumination with red light. Far-red light and darkness converts the molecule (Pfr) back to the inactive form. Although, it converts back to Pr, slowly in darkness
