Question 1

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

Accepted Answer

A) rapid growth response. 
B) potassium channels. 
C) nervous tissue. 
D) aquaporins. 
E) stress proteins. 
A) rapid growth response. 
B) potassium channels. 
C) nervous tissue. 
D) aquaporins. 
E) stress proteins.

Question 2

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

Accepted Answer

A) photosynthesis. 
B) seed germination. 
C) phototropism. 
D) flowering. 
E) entrainment of circadian rhythms. 
A) photosynthesis. 
B) seed germination. 
C) phototropism. 
D) flowering. 
E) entrainment of circadian rhythms.

Question 3

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

Accepted Answer

A) Different tissues have the same response to auxin. 
B) The effect of a plant hormone can depend on the tissue. 
C) Some responses of plants require no hormones at all. 
D) Light is required for the gravitropic response. 
E) Cytokinin can only function in the presence of auxin. 
A) Different tissues have the same response to auxin. 
B) The effect of a plant hormone can depend on the tissue. 
C) Some responses of plants require no hormones at all. 
D) Light is required for the gravitropic response. 
E) Cytokinin can only function in the presence of auxin.

Question 4

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

Accepted Answer

A) they need sunlight energy for photosynthesis. 
B) the sun stimulates stem growth. 
C) cell expansion is greater on the dark side of the stem. 
D) auxin is inactive on the dark side of the stem. 
E) phytochrome stimulates florigen production. 
A) they need sunlight energy for photosynthesis. 
B) the sun stimulates stem growth. 
C) cell expansion is greater on the dark side of the stem. 
D) auxin is inactive on the dark side of the stem. 
E) phytochrome stimulates florigen production.

Question 5

Unlike animal hormones, plant hormones are mainly

Accepted Answer

A) hydrophobic molecules. 
B) products of stresses in the environment. 
C) small, easily transportable molecules. 
D) unable to cross membranes. 
E) direct products of photosynthesis. 
A) hydrophobic molecules. 
B) products of stresses in the environment. 
C) small, easily transportable molecules. 
D) unable to cross membranes. 
E) direct products of photosynthesis.

Question 6

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

Accepted Answer

A) antisense RNA. 
B) Pfr phytochrome. 
C) salicylic acid. 
D) abscisic acid. 
E) red, but not far-red, light. 
A) antisense RNA. 
B) Pfr phytochrome. 
C) salicylic acid. 
D) abscisic acid. 
E) red, but not far-red, light.

Question 7

The hormone that helps plants respond to drought is

Accepted Answer

A) auxin. 
B) gibberellin. 
C) cytokinin. 
D) ethylene. 
E) abscisic acid. 
A) auxin. 
B) gibberellin. 
C) cytokinin. 
D) ethylene. 
E) abscisic acid.

Question 8

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

Accepted Answer

A) far-red light during the night. 
B) red light during the night. 
C) red light followed by far-red light during the night. 
D) far-red light during the day. 
E) red light during the day. 
A) far-red light during the night. 
B) red light during the night. 
C) red light followed by far-red light during the night. 
D) far-red light during the day. 
E) red light during the day.

Question 9

According to the acid growth hypothesis, auxin works by

Accepted Answer

A) dissolving sieve plates, permitting more rapid transport of nutrients. 
B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. 
C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. 
D) increasing wall plasticity and allowing the affected cell walls to elongate. 
E) greatly increasing the rate of deposition of cell wall material. 
A) dissolving sieve plates, permitting more rapid transport of nutrients. 
B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. 
C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. 
D) increasing wall plasticity and allowing the affected cell walls to elongate. 
E) greatly increasing the rate of deposition of cell wall material.

Question 10

Which of the following treatments would enhance the level of the Pfr form of phytochrome?

Accepted Answer

A) exposure to far-red light 
B) exposure to red light 
C) long dark period 
D) inhibition of protein synthesis 
E) synthesis of phosphorylating enzymes 
A) exposure to far-red light 
B) exposure to red light 
C) long dark period 
D) inhibition of protein synthesis 
E) synthesis of phosphorylating enzymes

Question 11

Trees found at high elevations tend to be short with stocky tree trunks compared to trees growing in more sheltered areas. The term that describes plants' sensitivity to mechanical stress is

Accepted Answer

A) thigmomorphogenesis. 
B) thigmotropism. 
C) statolithogenesis. 
D) florigenesis. 
E) vernalization. 
A) thigmomorphogenesis. 
B) thigmotropism. 
C) statolithogenesis. 
D) florigenesis. 
E) vernalization.

Question 12

We tend to think of plants as immobile when, in fact, they can move in many ways. Which of the following is a legitimate way in which plants move?

Accepted Answer

A) stretching or shrinking movements up or down in response to light 
B) folding and unfolding of leaves using muscle-like tissues 
C) growth movements toward or away from light 
D) cessation of plant growth in response to wind or touch 
E) rapid responses using action potentials from nervous tissue cells similar to those found in the nervous tissue of animals 
A) stretching or shrinking movements up or down in response to light 
B) folding and unfolding of leaves using muscle-like tissues 
C) growth movements toward or away from light 
D) cessation of plant growth in response to wind or touch 
E) rapid responses using action potentials from nervous tissue cells similar to those found in the nervous tissue of animals

Question 13

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only ¼ inch of soil is that the

Accepted Answer

A) seedlings do not produce a hypocotyl. 
B) seedlings do not have an etiolation response. 
C) seeds require light to germinate. 
D) seeds require a higher temperature to germinate. 
E) seeds are very sensitive to waterlogging. 
A) seedlings do not produce a hypocotyl. 
B) seedlings do not have an etiolation response. 
C) seeds require light to germinate. 
D) seeds require a higher temperature to germinate. 
E) seeds are very sensitive to waterlogging.

Question 14

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

Accepted Answer

A) calcium release from the endoplasmic reticulum of shaded cells. 
B) whether the plant is in the northern or southern hemisphere. 
C) gibberellin production by stems. 
D) auxin production in cells receiving red light. 
E) auxin movement toward the lower side of the stem. 
A) calcium release from the endoplasmic reticulum of shaded cells. 
B) whether the plant is in the northern or southern hemisphere. 
C) gibberellin production by stems. 
D) auxin production in cells receiving red light. 
E) auxin movement toward the lower side of the stem.

Question 15

Auxin enhances cell elongation in all of the these ways except

Accepted Answer

A) increased uptake of solutes. 
B) gene activation. 
C) acid-induced denaturation of cell wall proteins. 
D) increased activity of plasma membrane proton pumps. 
E) cell wall loosening. 
A) increased uptake of solutes. 
B) gene activation. 
C) acid-induced denaturation of cell wall proteins. 
D) increased activity of plasma membrane proton pumps. 
E) cell wall loosening.

Question 16

Which of the following would be the most effective way to prevent herbivory in a non-woody plant?

Accepted Answer

A) production of the amino acid analogue canavanine 
B) release of insect pheromones 
C) production of foul-tasting compounds 
D) thickened cuticle 
E) enhanced levels of salicylic acid 
A) production of the amino acid analogue canavanine 
B) release of insect pheromones 
C) production of foul-tasting compounds 
D) thickened cuticle 
E) enhanced levels of salicylic acid

Exam 39: Plant Responses to Internal and External Signals

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

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

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

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

Unlike animal hormones, plant hormones are mainly

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

The hormone that helps plants respond to drought is

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

According to the acid growth hypothesis, auxin works by

Which of the following treatments would enhance the level of the Pfr form of phytochrome?

Trees found at high elevations tend to be short with stocky tree trunks compared to trees growing in more sheltered areas. The term that describes plants' sensitivity to mechanical stress is

We tend to think of plants as immobile when, in fact, they can move in many ways. Which of the following is a legitimate way in which plants move?

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only ¼ inch of soil is that the

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

Auxin enhances cell elongation in all of the these ways except

Which of the following would be the most effective way to prevent herbivory in a non-woody plant?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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