Review Questions
The main photoreceptor that triggers phototropism is a ________.
- phytochrome
- cryptochrome
- phototropin
- carotenoid
Hint:
C
Phytochrome is a plant pigment protein that:
- mediates plant infection
- promotes plant growth
- mediates morphological changes in response to red and far-red light
- inhibits plant growth
Hint:
C
A mutant plant has roots that grow in all directions. Which of the following organelles would you expect to be missing in the cell?
- mitochondria
- amyloplast
- chloroplast
- nucleus
Hint:
B
After buying green bananas or unripe avocadoes, they can be kept in a brown bag to ripen. The hormone released by the fruit and trapped in the bag is probably:
- abscisic acid
- cytokinin
- ethylene
- gibberellic acid
Hint:
C
A decrease in the level of which hormone releases seeds from dormancy?
- abscisic acid
- cytokinin
- ethylene
- gibberellic acid
Hint:
A
A seedling germinating under a stone grows at an angle away from the stone and upward. This response to touch is called ________.
- gravitropism
- thigmonasty
- thigmotropism
- skototropism
Hint:
C