A scientist is researching the germination rates of different Arabidopsis thaliana mutants. The seeds from one of her mutants always fails to germinate, even if she exposes them to red light. In these plants, what might the mutation affect?

Question

Quizplus · Accepted Answer

The fact that the mutant seeds fail to germinate even when exposed to red light suggests that the mutation may be affecting a crucial step in the conversion of phytochrome, the red light photoreceptor protein, from its inactive form (PHYr) to its active form (PHYfr). Therefore, option B, which suggests that the mutation inhibits the conversion of PHYr to PHYfr, is the best choice.

A Scientist Is Researching the Germination Rates of Different Arabidopsis