Question 1

The rapid closure of leaves of the Venus flytrap is now thought to be due to:

Accepted Answer

A) changes in turgor pressure in the cells beneath the epidermis. 
B) changes in turgor pressure in the upper epidermis. 
C) changes in turgor pressure in cells of the pulvinus. 
D) acid-induced wall loosening of motor cells. 
E) unloading of sucrose from the phloem. 
A) changes in turgor pressure in the cells beneath the epidermis. 
B) changes in turgor pressure in the upper epidermis. 
C) changes in turgor pressure in cells of the pulvinus. 
D) acid-induced wall loosening of motor cells. 
E) unloading of sucrose from the phloem.

Question 2

The seismonastic movements of Mimosa pudica involve changes in the pulvini.

Accepted Answer

A) True 
 B)False

Question 3

The ageotropum mutant of pea plants lacks both a hydrotropic response and a gravitropic response.

Accepted Answer

A) True 
 B)False

Question 4

The sleep movements of plants are an example of nastic movements.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following statements concerning photoperiodism is FALSE?

Accepted Answer

A) Short-day plants in the early spring or fall. 
B) Spinach and lettuce are examples of long-day plants. 
C) Day-neutral plants flower without respect to photoperiod. 
D) Photoperiodic behavior remains constant over a wide range of temperatures. 
E) In some plants, only a single exposure to the critical day-length will produce a response. 
A) Short-day plants in the early spring or fall. 
B) Spinach and lettuce are examples of long-day plants. 
C) Day-neutral plants flower without respect to photoperiod. 
D) Photoperiodic behavior remains constant over a wide range of temperatures. 
E) In some plants, only a single exposure to the critical day-length will produce a response.

Question 6

Stratification is the process used by horticulturalists in which seeds are:

Accepted Answer

A) moistened and exposed to low temperature. 
B) moistened and exposed to high temperature. 
C) mechanically abraded. 
D) soaked in alcohol. 
E) dried. 
A) moistened and exposed to low temperature. 
B) moistened and exposed to high temperature. 
C) mechanically abraded. 
D) soaked in alcohol. 
E) dried.

Question 7

Photoperiodism pertains to events that are influenced by the relative lengths of light and dark.

Accepted Answer

A) True 
 B)False

Question 8

In contrast to thigmonastic movements, thigmomorphogenesis:

Accepted Answer

A) is a response to touch. 
B) is a response to a mechanical stimulus. 
C) is independent of the direction of the stimulus. 
D) involves cells of the pulvinus. 
E) involves an altered growth pattern. 
A) is a response to touch. 
B) is a response to a mechanical stimulus. 
C) is independent of the direction of the stimulus. 
D) involves cells of the pulvinus. 
E) involves an altered growth pattern.

Question 9

The direction of a nastic movement is always ______ the direction of the stimulus.

Accepted Answer

A) away from 
B) toward 
C) at right angles to 
D) at an oblique angle to 
E) independent of 
A) away from 
B) toward 
C) at right angles to 
D) at an oblique angle to 
E) independent of

Question 10

The florigen FT is produced in:

Accepted Answer

A) vessel elements. 
B) companion cells. 
C) tracheids. 
D) sieve-tube elements. 
E) guard cells. 
A) vessel elements. 
B) companion cells. 
C) tracheids. 
D) sieve-tube elements. 
E) guard cells.

Question 11

According to the original hypothesis on negative gravitropism of shoots, auxin is redistributed to the ______ side where it ______ cell expansion.

Accepted Answer

A) lower; stimulates 
B) lower; inhibits 
C) upper; stimulates 
D) upper; inhibits 
E) upper; first inhibits then stimulates 
A) lower; stimulates 
B) lower; inhibits 
C) upper; stimulates 
D) upper; inhibits 
E) upper; first inhibits then stimulates

Question 12

With respect to effect on flowering, the middle of the dark period is the part most sensitive to interruption by a flash of light.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following statements about bud scales is FALSE?

Accepted Answer

A) They may contain growth inhibitors. 
B) They protect the bud against desiccation. 
C) They restrict the movement of oxygen into the bud. 
D) They insulate the bud from heat loss. 
E) They have leaf primordia in their axils. 
A) They may contain growth inhibitors. 
B) They protect the bud against desiccation. 
C) They restrict the movement of oxygen into the bud. 
D) They insulate the bud from heat loss. 
E) They have leaf primordia in their axils.

Question 14

Vernalization is the exposure of flower buds to low temperatures to promote early flowering.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following statements about circadian clocks is FALSE?

Accepted Answer

A) Input pathways and output pathways are the parts of the clock that do not interact. 
B) Conceptually they consist of three parts. 
C) They cause the regular oscillation of 30-40 percent of Arabidopsis genes. 
D) The central oscillator is the part of the clock that generates rhythmic behavior. 
E) Input pathways are the part of the clock that carries information to the oscillator. 
A) Input pathways and output pathways are the parts of the clock that do not interact. 
B) Conceptually they consist of three parts. 
C) They cause the regular oscillation of 30-40 percent of Arabidopsis genes. 
D) The central oscillator is the part of the clock that generates rhythmic behavior. 
E) Input pathways are the part of the clock that carries information to the oscillator.

Question 16

In nyctinastic movements, leaves:

Accepted Answer

A) twine around a support such as a fence post. 
B) have their stomata open during the night and closed during the day. 
C) are rolled during the day and unrolled at night. 
D) are oriented vertically in darkness and horizontally in light. 
E) are oriented horizontally in darkness and vertically in light. 
A) twine around a support such as a fence post. 
B) have their stomata open during the night and closed during the day. 
C) are rolled during the day and unrolled at night. 
D) are oriented vertically in darkness and horizontally in light. 
E) are oriented horizontally in darkness and vertically in light.

Question 17

Experiments on cocklebur have shown that the ______ perceives the photoperiod.

Accepted Answer

A) apical meristem 
B) columella 
C) leaf blade 
D) petiole 
E) stem 
A) apical meristem 
B) columella 
C) leaf blade 
D) petiole 
E) stem

Question 18

Regular rubbing or bending of a stem stimulates its elongation.

Accepted Answer

A) True 
 B)False

Question 19

In the process of vernalization, early ______ is stimulated by exposing the germinating seeds to ______ temperatures.

Accepted Answer

A) dormancy; low 
B) flowering; low 
C) germination; low 
D) dormancy; high 
E) germination; high 
A) dormancy; low 
B) flowering; low 
C) germination; low 
D) dormancy; high 
E) germination; high

Question 20

In the current model of root gravitropism, elongation is _____ in the upper side of the distal elongation zone and ______ along the lower side.

Accepted Answer

A) stimulated; stimulated 
B) stimulated; suppressed 
C) suppressed; stimulated 
D) suppressed; is neither stimulated nor suppressed 
E) is neither stimulated nor suppressed; suppressed 
A) stimulated; stimulated 
B) stimulated; suppressed 
C) suppressed; stimulated 
D) suppressed; is neither stimulated nor suppressed 
E) is neither stimulated nor suppressed; suppressed

Exam 28: External Factors and Plant Growth

The rapid closure of leaves of the Venus flytrap is now thought to be due to:

The seismonastic movements of Mimosa pudica involve changes in the pulvini.

The ageotropum mutant of pea plants lacks both a hydrotropic response and a gravitropic response.

The sleep movements of plants are an example of nastic movements.

Which of the following statements concerning photoperiodism is FALSE?

Stratification is the process used by horticulturalists in which seeds are:

Photoperiodism pertains to events that are influenced by the relative lengths of light and dark.

In contrast to thigmonastic movements, thigmomorphogenesis:

The direction of a nastic movement is always ______ the direction of the stimulus.

The florigen FT is produced in:

According to the original hypothesis on negative gravitropism of shoots, auxin is redistributed to the ______ side where it ______ cell expansion.

With respect to effect on flowering, the middle of the dark period is the part most sensitive to interruption by a flash of light.

Which of the following statements about bud scales is FALSE?

Vernalization is the exposure of flower buds to low temperatures to promote early flowering.

Which of the following statements about circadian clocks is FALSE?

In nyctinastic movements, leaves:

Experiments on cocklebur have shown that the ______ perceives the photoperiod.

Regular rubbing or bending of a stem stimulates its elongation.

In the process of vernalization, early ______ is stimulated by exposing the germinating seeds to ______ temperatures.

In the current model of root gravitropism, elongation is _____ in the upper side of the distal elongation zone and ______ along the lower side.

Botany: an Introduction

The Molecular Composition of Plant Cells

The Plant Cell and the Cell Cycle

The Movement of Substances Into and Out of Cells

The Flow of Energy

Respiration

Photosynthesis, Light, and Life

Sexual Reproduction and Heredity

The Chemistry of Heredity and Gene Expression

Recombinant Dna Technology, Plant Biotechnology, and Genomics

The Process of Evolution

Systematics: the Science of Biological Diversity

Prokaryotes and Viruses

Fungi

Protists: Algae and Heterotrophic Protists

Bryophytes

Seedless Vascular Plants

Gymnosperms

Introduction to the Angiosperms

Evolution of the Angiosperms

Plants and People

Early Development of the Plant Body

Cells and Tissues of the Plant Body

The Root: Structure and Development

The Shoot: Primary Structure and Development

Secondary Growth in Stems

Regulating Growth and Development: the Plant Hormones

Plant Nutrition and Soils

The Movement of Water and Solutes in Plants

The Dynamics of Communities and Ecosystems

Global Ecology

Filters

According to the original hypothesis on negative gravitropism of shoots, auxin is redistributed to the side where it cell expansion.

In the process of vernalization, early is stimulated by exposing the germinating seeds to temperatures.

In the current model of root gravitropism, elongation is _ in the upper side of the distal elongation zone and __ along the lower side.