Exam 39: Plant Signals and Behavior

Which of the following describes a difference between hormonal regulation in plants compared to animals?

Which hormone prevents seeds from germinating until conditions are favorable for the growth of the plant?

Suppose a plant had a photosynthetic pigment that absorbed far-red wavelengths of light. In which of the following environments is the plant most likely to thrive?

Auxins frequently interact with other plant hormones to cause a particular process. Which of the following processes is attributed ONLY to auxin?

What are the primary sites of auxin (IAA) production in plants?

If you were shipping green bananas to a supermarket thousands of miles away, removing which of the following chemicals from the plants' environment will best prevent premature fruit ripening?

If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering?

Plants often use changes in day length (photoperioD) to trigger events such as dormancy and flowering. Which of the following best explains why day-neutral plants are more common in the tropics than in temperate zones?

A population of plants experienced several years of severe drought. Most of the plants died due to lack of water, but a few individuals survived. The surviving plants probably produced higher levels of which of the following hormones?

Which type of mutant is most likely to produce a bushier phenotype?

Unlike animal hormones, plant hormones can have multiple functions depending on which of the following factors? I. site of action II. concentration III. developmental stage IV. chronological age

How may a plant respond to severe heat stress?

The hormone that helps plants respond to drought is ________.

Upon exposure to blue light, plants not only begin to grow toward the light, but redistribute the chloroplasts to the sunny side of each cell. Which of the following best explains the adaptive advantage of moving chloroplasts to the sunny side of each cell?

Many plants flower in response to day-length cues. Which of the following statements correctly describes the relationship between day length and flowering?

You have a small tree in your yard that is the height that you want it, but does not have as many branches as you want. Which of the following pruning strategies will trigger increased branching?

In an experiment investigating phototropism, pieces of shoot apices were applied to small blocks of agar with light shining from one side only. The apices were either partly or completely divided in two with a barrier that also divided the blocks. The figure summarizes the results of the experiment. Numbers indicate the percent of auxin moving from the apex into the agar segment below it. Which of the following hypotheses is best supported by the data?

Cytokinins, produced primarily in roots, travel by which of the following structures to influence branching in a recently topped tree (tree whose upper branches have been trimmed off)?

The signaling molecule for flowering might be released earlier than usual in a long-day plant exposed to flashes of ________.

Which event during the evolution of land plants favored the synthesis of secondary compounds?