Exam 39: Plant Signals and Behavior

Which one of the following hormones stimulate(s) rapid stem elongation (straight growth) and pollen tube growth?

What are the sites of highest ethylene production in plants?

Shoots can be characterized as which of the following?

Which of the following is an evolutionary adaptation for a plant growing in darkness?

Which of the following hormones primarily function(s) to regulate plant cell division?

Vines in tropical rain forests must grow toward large trees before being able to climb toward the sun. Which of the following responses would promote vine growth towards a tree?

Charles Darwin and his son Francis did a series of experiments to test their hypothesis that the tips of grass coleoptiles sense the direction of light. In the first experiment, coleoptiles with their tips cut off did not bend toward light, but intact coleoptiles did. Why was it necessary to follow this experiment with another experiment where only the tips of treated coleoptiles were covered with opaque foil?

Which of the following plant parts elongate in response to etiolation during seedling germination? I. Roots II. Hypocotyl III. Internodes IV. Leaves

Auxin enhances cell elongation in all of these ways except ________.

Which of the following statements best summarizes the acid growth hypothesis in an actively growing shoot?

Which of the following can be involved in the mechanism of plant hormone function? I. altering the expression of genes II. modifying the permeability of the plasma membrane III. modifying the structure of the nuclear envelope

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.

Which of the following terms describes a generalized defense response in organs that are distant a site of infection?

Phytochrome plays a critical role in germination of some seeds. Which of these colors of light maximizes germination in these seeds?

The following steps occur during a plant's response to drought stress. I. ABA accumulates in the leaves II. stomata close III. transpiration decreases IV. guard cell potassium channels open Which of the following places the steps in the correct sequence to represent the acquisition of drought tolerance in the plant?

Which of the following illustrates a commercial application of cytokinins?

You are out working in your garden, and you notice that one of your favorite flowering plants has black, dead spots on the leaves. Which of the following is most likely responsible for the symptoms you observe?

Four physiological events that occur during de-etiolation (greening) of plants are listed below. I. detection of light signal II. activation of phytochrome III. activation of specific protein kinase1 IV. formation of de-etiolation response protein Which of the following lists these events in the correct order?

In the fall, the leaves of some trees change color. This happens because chlorophyll breaks down and the accessory pigments become visible. What hormone triggers this response in plants?

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