Mammalian eyes sense light because the photoreceptor cells have molecules called opsins, which change structure when exposed to light. Which of the following plant molecules would be analogous to mammalian opsins in their light-sensing ability?
A) auxin and phytochrome
B) auxin and Pfᵣ
C) Pfᵣ and phytochrome
D) cytokinins and phototropins

Question

Quizplus · Accepted Answer

Pfᵣ and phytochrome are both plant molecules that are involved in light-sensing. Pfᵣ is a blue light receptor and phytochrome is a red/far-red light receptor. Both of these molecules undergo conformational changes when exposed to light, similar to the way that opsins in mammalian eyes change structure when exposed to light. Auxin and cytokinins are plant hormones, and phototropins are involved in plant growth and orientation towards light, but they are not directly involved in light-sensing like Pfᵣ and phytochrome.

Mammalian Eyes Sense Light Because the Photoreceptor Cells Have Molecules