37. Plant Sensation and Response

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

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

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.

Which hormone would a florist most likely spray on cut flowers to keep them fresh?

As leaf lettuce matures, a tall flowering shoot extends beyond the basal, edible leaves. After the plant bolts like this, it no longer produces broad, tasty leaves. Suppose you want to prevent bolting so that you can harvest lettuce longer. You may want to prevent the plant from synthesizing __________.

Increasing the cytoplasmic levels of specific well-tolerated solutes, such as sugars, helps a plant to cope with __________.

Increasing the proportion of unsaturated fatty acids in their membranes is a response of plants to __________.

How are heat-shock proteins thought to work?

Which of the following describes a plant's response to heat stress?

Seeds of many desert plants will not germinate until a heavy rain washes away their __________.

The triple response to mechanical stress results in __________.

The abscission layer __________.

In the autumn, the amount of __________ decreases, rendering the cells of the abscission layer more sensitive to __________.

The synthesis and release of abscisic acid in a plant is a response to __________.

Which of these features is/are characteristic of ethylene?

__________ appear to allow a plant cell to sense its orientation with respect to gravity.

A rapid loss of water in specialized cells in the sensitive plant Mimosa pudica causes __________.

The formation of air tubes in submerged roots is an adaptation to __________.

The production of organic solutes by plants is a response to __________.

When a plant that is not adapted to salty water is exposed to salty water, it will __________.

Test your knowledge of the five major classes of plant hormones (auxins, cytokinins, gibberellins, abscisic acid, ethylene) by matching one hormone to each lettered box. (Note that some hormones will match up to more than one box.)

During winter or periods of drought, which one of the following plant hormones inhibits growth and seed germination? a. ethylene b. abscisic acid c. gibberellin d. auxin

In autumn, the amount of _________ increases and the amount of _________ decreases in fruits and leaf stalks, causing a plant to drop fruit and leaves. a. ethylene … auxin b. gibberellin … abscisic acid c. cytokinin … abscisic acid d. auxin … ethylene

Plant hormones act by affecting the activities of a. genes. b. membranes. c. enzymes. d. genes, membranes, and enzymes.

Buds and sprouts often form on tree stumps. Which hormone would stimulate their formation? a. auxin b. cytokinin c. abscisic acid d. ethylene

"Match each definition with the correct term. Bending of a shoot toward light Growth response to touch Cycle with a period of about 24 hours Pigment that helps control flowering Relative lengths of night and day Growth response to gravity Folding of plant leaves at night a. phytochrome b. photoperiod c. sleep movement d. circadian rhythm e. thigmotropism f. phototropism g. gravitropism"

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

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