The immediate, direct effect of auxin in cell elongation, according to the acid growth hypothesis, is to __________.

If apples are to be stored for long periods, it is best to keep them in a place with good air circulation. Explain why.

Leaflets of Mimosa pudica (common names: sensitive plant, touch-me-not) have a remarkable ability to close up in response to being touched or physically moved. How fast can the leaflets close? How does this occur? And more importantly, what benefit could this unusual response provide to the plant?Mimosa leaflets also close on their own at dusk and reopen at dawn (this cycle develops as a circadian rhythm). What receptor molecule mentioned in this chapter is likely involved in regulating this process?

Write a short paragraph explaining why a houseplant becomes bushier if you pinch off its terminal buds.

What is growth that results in curvatures of whole plant organs toward or away from stimuli called?

In addition to interacting with auxin in the control of apical dominance, newly discovered plant hormones help to establish mycorrhizal associations by attracting mycorrhizal fungi to the plant roots. What are these hormones called?

A graduate student growing plant cells in a laboratory dish wants them to __________; therefore, the student treats them with cytokinins.

A callus will develop roots if you use a __________ auxin concentration and a __________ cytokinin concentration in the medium.

In shoots, branching is inhibited by __________ from the tip of a growing shoot, but this effect is countered by __________ from the roots.