The detector of light during de-etiolation (greening) of a tomato plant is (are) ________.

Plant hormones ________.

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

Which of the following mechanisms is in the correct sequence of steps (I-IV as listed below) that takes place during the formation of de-etiolation (greening) response proteins in plants?

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 can function in signal transduction in plants?

I. calcium ions
II. nonrandom mutations
III. receptor proteins
IV. autochrome
V. secondary messengers

Plant hormones produce their effects by ________.

I. altering the expression of genes
II. modifying the permeability of the plasma membrane
III. modifying the structure of the nuclear envelope membrane

Plant hormonal regulation differs from animal hormonal regulation in that ________.

Auxins in plants are known to affect which of the following processes?

I. gravitropism of shoots
II. maintenance of seed dormancy
III. phototropism of shoots
IV. inhibition of lateral buds
V. apical dominance

Experiments on the positive phototropic response of plants indicate that ________.

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

What are the primary sites of ethylene production in high concentrations in plants?

Which one of the following hormones regulates cell division in plants?

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

Generally, each hormone has multiple functions in plants depending on ________.

I. site of action
II. its concentration
III. developmental stage
IV. age

Apical dominance in plants is under the control of ________.

Arrange the following steps that occur during drought tolerance in plants in a correct sequence.

I. hormone ABA accumulation in the leaves
II. causes stomata to close
III. reduction in transpiration
IV. preventing further water loss

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

Which of the following conclusions is supported by the research of both Peter Boysen-Jensen and Charles and Francis Darwin on shoot responses to light?

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?

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. How can you prune it to trigger it to increase the number of branches?

) As cytokinins are primarily produced in roots, what route would they travel to influence lateral shoot formation in a recently topped tree?

Who might be interested in using cytokinins?

If a farmer wanted more loosely packed clusters of grapes, he would most likely spray the immature bunches with ________.

________ prevents seeds from germinating until conditions are favorable for the growth of the plant.

A population of plants experiences several years of severe drought. Much of the population dies due to lack of water, but a few individuals survive. You set out to discover the physiological basis for their adaptation to such an extreme environmental change. You hypothesize that the survivors have the ability to synthesize higher levels of ________ than their siblings do

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?

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?

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

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 ________.

Upon exposure to blue light, plants not only begin to grow toward the light, but move their chloroplasts to the sunny side of each cell. The adaptive advantage of moving chloroplasts to the sunny side of each cell ________.

Mammalian eyes sense light because the photoreceptor cells have molecules called opsins, which change structure when exposed to light. Which of the following plant molecules would be analogous to mammalian opsins in their light-sensing ability?

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 ________.

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

The biological clock controlling circadian rhythms must ultimately ________.

Which of the colors of visible light induces curvature in coleoptile most effectively?

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

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

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

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 environmental factors can be sensed by plants?

I) gravity
II) pathogens
III) wind
IV) light

Shoots that grow vertically toward the sun can be characterized as ________.

The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve ________.

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

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?

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

You are out working in your garden, and you notice that one of your favorite flowering plants has black, dead spots on the leaves. You immediately suspect that the plant has been invaded by a pathogen and has initiated a(n) ________.

Generalized defense responses in organs distant from the infection site are called ________.

A particular species of virus carries a gene for salicylate hydroxylase, an enzyme that breaks down salicylic acid. Will this virus be more or less virulent to plants than other viruses?

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

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

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?

A plant scientist was hired by a greenhouse operator to devise a way to force iris plants to bloom in the short days of winter. Iris normally blooms as a long-day (short-night) plant. Which of the following has the best chance of creating iris blooms in winter?

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?

The hormone that helps plants respond to drought is

Auxin enhances cell elongation in all of these ways except

Charles and Francis Darwin discovered that

How may a plant respond to severe heat stress?

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

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

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.