Chapter 39: Practice Test Flashcards

Which of the following statements about plant hormones is false?

Negative gravitropism of plant shoots

Many plants flower in response to day-length cues. Which statement concerning flowering false?

How may a plant respond to severe heat stress?

Auxins (IAA) in plants are known to affect all of the following phenomena except

Plants growing in a partially dark environment will grow toward light in a response called phototropism. Choose the incorrect statement regarding phototropism.

A plant will recognize a pathogenic invader

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

We tend to think of plants as immobile when, in fact, they can move in many ways. All of the following are movements plants are accomplish except

Ethylene, as an example of a plant hormone, may have multiple effects on a plant, depending on all of the following except the

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

If a scientist discovers an Arabidopsis mutant that does not store starch in plastids has normal gravitropic bending, what aspect of our understanding would need to be reevaluated?

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

Most plants close their stomata at night. What color of light would be effective in promoting stomatal opening in the middle of the night?

Regarding positive gravitropism exhibited by plant roots

Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have this mechanism because photoperiod changes

What would happen if the secondary messenger cGMP was clocked in the de-etiolation pathway?

After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to

You are part of a desert plant research team trying to discover crops that will be productive in arid climates. You discover a plant that produces a guard cell hormone under water-deficit conditions. Most likely the hormone is

In attempting to make a seed break dormancy, one logically could treat it

What is the probable role of salicylic acid in the defense response of plants

Both red and blue light are involved in

Which of the following is not presently considered a major mechanism whereby hormones control plant development?

Charles and Francis Darwin concluded from their experiments on phototropism by grass seedlings that the part of the seedling the detects the direction of light is the

In general, which of the following is not a plant response to herbivores?

Which of the following watering regimens will be most effective at keeping a lawn green during the hot, dry summer months?

When an arborist prunes a limb a valuable tree, he or she usually paints the cut surface. The primary purpose of the paint is to

Which plant hormones might be used to enhance stem elongation and fruit growth?

Incandescent light bulbs, which have high output of red light, are least effective in promoting

According to modern ideas about phototropism in plants

A pathogenic fungus invades a plant. What does the infected produce in response to the attack?

The results of this experiment, shown on the left of the graph (area A) may be used to

Plant growth regulators can be characterized by all of the following except that they

All of the following are responses of plants to cold stress except

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?

According to the acid growth hypothesis, auxin works by

Bald cypress and Loblolly pine are both gymnosperm trees native to the southern United States. The cypress grows in swamps; the pine grows in sandy soil. How do you think their anatomies differ?

The hormone that helps plants respond to drought is

Which one of the following is not a direct function of either auxin or gibberellin?

When growing plants in culture, IAA is used to stimulate cell enlargement. Which plant growth regulator has to now be added to stimulate cell division?

Auxin enhances cell elongation in all of these ways except

Plants that have their flowering inhibited by being exposed to bright lights at night are

Plant cells begin synthesizing large quantities of heat-shock proetins

Which of the following does not reduce the level of the Pfr form of phytochrome?

The apical bud of a pine tree inhibits the growth of lateral buds through the production of

This experiment suggests that the unknown amount of gibberellin in experimental plant (B) is approximately

External stimuli would be received most quickly by a plant cell if the receptors for signal transduction were located in the

Which of the following is not a typical component of a signal transduction pathway?

Biological clocks cause organisms to perform daily activities on a regular basis. Which of the following is a false statement about this kind of "circadian rhythm?"

The biological clock controlling circadian rhythms must ultimately

The ripening of fruit and the dropping of leaves and fruit are principally controlled by

A long-day plant will flower if

Why might animal hormones function differently from plant hormones?

Cells elongate in response to auxin. All of the following are part of the acid growth hypothesis except

If the range of species of plants expands to a higher latitude, which of the following processes is the most likely to be modified by natural selection?

Which of the following is currently the most powerful method of research on plant hormones?

A botanist exposed two groups of the same plant species to two photoperiods–one with 14 hours of light and 10 hours of dark and the other with 10 hours of light and 14 hours of dark. Under the first set of conditions, the plants flowered, but they failed to flower under the second set of conditions. Which of the following conclusions would be consistent with these results?

What do results of research on gravitropic responses of roots and stems show?

Why do coleoptiles grow toward light?

In systemic acquired resistance, salicylic acid probably

If a short-day plant has a critical night length of 15 hours, then which of the following 24-hour cycles will prevent flowering?

Plant hormones produce their effects

Which of the following has not been established as an aspect of auxin's role in cell elongation?

We know from the experiments of the past that plants bend toward light because

Auxin is responsible for all of the following plant growth responses except

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

All of the following may function in signal transduction in plants except

Oat seedlings are sometimes used to study auxins because

A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant likely

The plant hormone involved in aging and ripening of fruit is

Classic experiments suggested that a floral stimulus Florigen could move across a graft from an induced plant to a noninduced plant and trigger flowering. Recent evidence using Arabidopsis has recently shown that florigen is probably

Which hormone is incorrectly paired with its function?

The houseplants in a windowless room with only fluorescent lights begin to grow tall and leggy. Which of the following treatments would promote more normal growth?

The chemical signal for flowering could be released earlier than normal in a long-day plant exposed to flashes of

The heavy line in Figure 39.1 illustrates the relationship between auxin concentration and cell growth in stem tissues. If the same range of concentrations were applied to lateral buds, what curve would probably be produced?

Vines in tropical rain forests must grow toward large trees before being able to grow toward the sun. To reach a large tree, the most useful kind of growth movement for a tropical vine presumably would be the opposite of

In nature, poinsettias bloom in early March. Research has shown that the flowering process is triggered three months before blooming occurs. In order to make poinsettias bloom in December, florists change the length of the light-dark cycle in September. Given the information and clues above, which of the following is a false statement about poinsettias?

Auxin triggers the acidification of cell walls that results in rapid growth, but also stimulates sustained, long-term cell elongation. What best explains how auxin brings about this dual growth response?

A plant seedling bends toward sunlight because

Which of the following are defenses that some plants use against herbivory?

Most scientists agree that global warming is underway; thus it is important to know how plants respond to heat stress. Which of the following is an immediate short-term response of plants to heat stress?

The synthesis of which of the following hormones would be a logical first choice in an attempt to produce normal growth in mutant dwarf plants?

Which of the following are examples or parts of plants' systemic acquired resistance against infection?

Buds and sprouts often form on tree stumps. Which of the following hormones would you expect to stimulate their formation?

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

One effect of gibberellins is to stimulate cereal seeds to produce

Plant hormones can have different effects at different concentrations. This explains how

Plants are affected by an array of pathogens. Which of the following is not a plant defense against disease?

Which of these conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light?

Which plant hormone(s) is (are) most closely associated with cell division?

If protein synthesis was blocked in etiolated cells, what would be necessary for the "greening" of these cells?

If you wanted to genetically engineer a plant to be more resistant to drought, increasing amounts of which of the following hormones might be a good first attempt?

Charles and Francis Darwin discovered that

The transduction pathway that activates systemic acquired resistance in plants is initially signaled by

In order for a plant to initiate chemical responses to herbivory,

The initial response of the root cells of a tomato plant watered with seawater would be to

How does indoleacetic acid affect fruit development?

A short-day plant will flower only when

In legumes, it has been shown that "sleep" movements are correlated with

What does a short-day plant need in order to flower?

A botanist discovers a plant that lacks the ability to form starch grains in root cells, yet the roots still grow downward. This evidence refutes the long-standing hypothesis that