Skip to main content
Ch. 39 - Plant Responses to Internal and External Signals

Chapter 39, Problem 3

Charles and Francis Darwin discovered that a. auxin is responsible for phototropic curvature. b. red light is most effective in shoot phototropism. c. light destroys auxin. d. light is perceived by the tips of coleoptiles.

Verified Solution
Video duration:
1m
This video solution was recommended by our tutors as helpful for the problem above.
1186
views
1
rank
Was this helpful?

Video transcript

Hi everyone never look at the question Charles and Francis Darwin discovered that light is perceived by and the Darwin's made that discovery that discovered the phenomenon of photo trumpism, which we will recall from our content videos is when a plant bends or grows towards the light. And one thing they did discover was that the light is perceived in a different part of the plant, then where the plant responds to that stimulus. So where they discovered that the plant perceives the light is at the tip of a little shoot. And the name for that Coley op tile is the little kind of protective sheath around a new shoot. And so they discovered that the light is perceived at the tips of those little shoots, so that is choice. A and that is our correct answer. It's not perceived at the base of calliope tiles or in the roots of the floral buds. This makes sense because as the little plant is growing, you want that shoot to be growing up towards the light. See you in the next video