Exam 39: Plant Responses to Internal and External Signals

Most scientists agree that global warming is underway; thus, it is important to know how plants respond to heat stress. Which of the following would be a useful line of inquiry to try and improve plant response and survival to heat stress?

An eccentric millionaire botanist has offered a $25,000 scholarship to anyone who can successfully get a plant to grow through a vertical maze in complete darkness. The maze is not in a box; the maze is simply drawn on the wall, and the contestants must get their plant to grow in a pattern that matches the path through the maze. You need the money and feel confident that you can accomplish this task. Which of the following techniques will help you succeed?

For a plant to initiate chemical responses to herbivory, before it is directly affected by herbivores, ________.

Many plants flower in response to day-length cues. Which of the following statements best summarizes this phenomenon?

Which of the following environmental factors can be sensed by plants? I gravity II pathogens III wind IV light

A gardener in Canada wants to surprise his mother on her birthday and make her favorite hibiscus bush flower in May instead of at the end of June. The bush is growing in the greenhouse. Which of the following might make the hibiscus bush flower early?

Which of the following mechanisms is the correct sequence of events that takes place during the plant responses to internal and external signals?

In extremely cold regions, woody species may survive freezing temperatures by ________.

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

Which one of the following hormones stimulates stem elongation and pollen tube growth?

If you were shipping green bananas to a supermarket thousands of miles away, which of the following chemicals would you want to eliminate from the plants' environment?

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only 1/4 inch of soil is that the ________.

A plant mutant that shows normal gravitropic bending but does not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

Phytochrome plays a critical role in seed germination. Which of the colors maximizes the seed germination?

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

Who might be interested in using cytokinins?

In the fall, the leaves of some trees change color. This happens because chlorophyll breaks down and the accessory pigments become visible. What hormone is responsible for this?

An individual plant was discovered that could not grow towards light. After some research, it was determined that the reason was a defective gene that did not allow for the level of cell elongation necessary for a phototropic response. This mutation greatly reduces the fitness of the individual plant. Which reason best describes the reason for the loss of fitness?

You may have observed plants rotate towards a light source, thereby increasing the plant's ability to intercept light energy and increase photosynthesis. You, however, are given the task of preventing grass seedlings from rotating toward the light. Using your knowledge of phototropism, which of the following experimental procedures would you use to complete your task?

Charles and Francis Darwin discovered that