37. Plant Sensation and Response

Which of the following is/are plant defenses against the herbivores that feed on them?

The first line of defense against pathogens is __________.

In at least some species of plant, a leaf damaged by a caterpillar may __________.

Which of the following is a type of defense used by plants to deter herbivores?a. chemicals toxic to the herbivoreb. chemicals that recruit other animalsc. spinesd. a, b, and c

Suppose that a mutant plant is unable to make methyl salicylate. Explain why it is not likely to survive in the wild.

A plant biologist observed a peculiar pattern when a tropical shrub was attacked by caterpillars. After a caterpillar ate a leaf, it would skip over nearby leaves and attack a leaf some distance away. Simply removing a leaf did not trigger the same change nearby. The biologist suspected that a damaged leaf sent out a chemical that signaled other leaves. How could this hypothesis be tested?

Imagine the following scenario: A plant biologist has developed a synthetic chemical that mimics the effects of a plant hormone. The chemical can be sprayed on apples before harvest to prevent flaking of the natural wax that is formed on the skin. This makes the apples shinier and gives them a deeper red color. What kinds of questions do you think should be answered before farmers start using this chemical on apples? How might the scientist go about finding answers to these questions?