Question

Phytochrome is a
A. Chromoprotein
B. Flavoprotein
C. Glycoprotein
D. Lipoprotein

Answer 1

Hint: Phytochrome is a pigmented protein that exists in two forms: Pr and Pfr. Pr absorbs the red light and further is converted to Pfr. The expression of many plant genes is regulated, and it may control plant development primarily through its role in regulating gene expression.

Complete answer:
A class of photoreceptors, phytochrome, present in plants, bacteria, and fungi used to detect light. They are light-sensitive, in the red and far-red region of the visible spectrum, and can be classed as either Type I, which are activated by far-red light, or Type II that is activated by the red light.
A chromoprotein is a conjugated protein that contains a cofactor or a pigmented prosthetic group. Phytochrome molecules are soluble chromoproteins that are organized along with a similar structural pattern in all plants that are investigated.
Flavoproteins are those proteins that contain a nucleic acid derivative of riboflavin. The derivative is flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN). Flavoproteins are involved in various biological processes. For instance, it includes the removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair.
Glycoproteins are molecules that comprise carbohydrate and protein chains that are involved in many physiological functions.
The function of these lipoproteins is to transport triglycerides and cholesterol from their origin to sites of use or uptake, such as the liver, muscle, and fat tissue.
So, the correct answer is “Option A”.

Note:
Chromoproteins are defined as proteins having pigmented prosthetic groups. Phy A and Phy B, regulate flowering in plants under different light conditions by absorption of red or far-red light by their pigment, are chromoprotein. It changes to Pfr at 670 nm of light, and at 730 nm of light, it changes to Pr.