4/9 lecture

Question 1

What is a photoreceptor?

Answer 1

molecule that absorbs lights and initiates some kind of signaling; usually a protein in biology

Question 2

3 plant photoreceptors:

Answer 2

• phytochrome
• cryptochrome
• phototropin

Question 3

What type of light does phytochrome perceive?

Answer 3

red and far-red light

Question 4

what type of light does cryptochrome perceive?

Answer 4

blue light

Question 5

what type of light does phototropin perceive?

Answer 5

blue light

Question 6

what does phytochrome regulate?

Answer 6

germination and shade avoidance

Question 7

what is photomorphogenesis?

Answer 7

growth or developmental change stimulated by light

Question 8

2 forms of phytochrome?

Answer 8

-inactive form (Pr)
- active form (Pfr)
depends on light conditions

Question 9

what is photoreversability?

Answer 9

ability of a photoreceptor to switch between active and non-active forms

Question 10

Where does Pr exist in the plant cell?

Answer 10

cytoplasm

Question 11

where does Pfr exist in the plant cell?

Answer 11

translocated to the nucleus