Question 1

Which of the following is the factor that initiates flowering in long-day plants?

Accepted Answer

A) nights shorter than a critical length 
B) nights longer than a critical length 
C) days longer than the intervening nights 
D) days shorter than a critical length 
A) nights shorter than a critical length 
B) nights longer than a critical length 
C) days longer than the intervening nights 
D) days shorter than a critical length A

Question 2

How does phytochrome control flowering?

Accepted Answer

A) by determining whether day length exceeds a critical minimum 
B) by determining whether day length is shorter than a critical maximum 
C) by sensing sunrise and sunset 
D) by inducing differentiation of cells in the apical meristem 
A) by determining whether day length exceeds a critical minimum 
B) by determining whether day length is shorter than a critical maximum 
C) by sensing sunrise and sunset 
D) by inducing differentiation of cells in the apical meristem C

Question 3

The event that triggers fruit formation is the growth of a pollen tube through the carpel of a flower. Which of the following is a reasonable hypothesis about the basis of this effect?

Accepted Answer

A) Pollen tubes grow in response to a cytokinin produced by the carpel. 
B) Pollen tubes grow in response to abscisic acid. 
C) The growing pollen tube produces ethylene. 
D) The growing pollen tube produces auxins and/or gibberellins. 
A) Pollen tubes grow in response to a cytokinin produced by the carpel. 
B) Pollen tubes grow in response to abscisic acid. 
C) The growing pollen tube produces ethylene. 
D) The growing pollen tube produces auxins and/or gibberellins. D

Question 4

Which of the following is a way that plants use animals as a defense against herbivores?

Accepted Answer

A) production of an amino acid that harms herbivores 
B) attraction of wasps that kill herbivorous caterpillars 
C) release of microbe-killing chemicals in response to infection 
D) coevolution between plants and predators 
A) production of an amino acid that harms herbivores 
B) attraction of wasps that kill herbivorous caterpillars 
C) release of microbe-killing chemicals in response to infection 
D) coevolution between plants and predators

Question 5

Which type of plant hormone generally acts as a growth inhibitor?

Accepted Answer

A) auxins 
B) gibberellins 
C) cytokinins 
D) abscisic acid 
A) auxins 
B) gibberellins 
C) cytokinins 
D) abscisic acid

Question 6

The plant growth response to touch is known as

Accepted Answer

A) gravitropism. 
B) geotropism. 
C) bolting. 
D) thigmotropism. 
A) gravitropism. 
B) geotropism. 
C) bolting. 
D) thigmotropism.

Question 7

In plant research labs, plants are often grown in light-proof chambers where the hours of light and dark are carefully controlled. A new researcher goes into a chamber and accidentally turns on the light during the "dark" period. What is likely to happen?

Accepted Answer

A) If the plants are short day plants, there will be no impact. 
B) If the researcher can quickly produce a flash of far-red light and close the door, there will be no impact. 
C) If the plants are not yet flowering, there will be no impact. 
D) If the light is only red light and not far-red light, there will be no impact. 
A) If the plants are short day plants, there will be no impact. 
B) If the researcher can quickly produce a flash of far-red light and close the door, there will be no impact. 
C) If the plants are not yet flowering, there will be no impact. 
D) If the light is only red light and not far-red light, there will be no impact.

Question 8

-If you cut off the top of a carrot and place it in water to see if you can get it to grow new roots, you should add

Accepted Answer

A) more than 10⁻² g/L of auxin. 
B) approximately 10⁻⁸ g/L of auxin. 
C) at least 10⁻⁶ g/L of auxin. 
D) equal amounts of auxin and cytokinin. 
A) more than 10⁻² g/L of auxin. 
B) approximately 10⁻⁸ g/L of auxin. 
C) at least 10⁻⁶ g/L of auxin. 
D) equal amounts of auxin and cytokinin.

Question 9

Which of the following is a good way to ripen a green, unripe fruit?

Accepted Answer

A) putting it in a darkened area such as a drawer or box 
B) placing it in a sealed plastic bag with an overripe banana 
C) placing it in a microwave, on low power, for 5 minutes 
D) placing it under a bright light for 24 hours 
A) putting it in a darkened area such as a drawer or box 
B) placing it in a sealed plastic bag with an overripe banana 
C) placing it in a microwave, on low power, for 5 minutes 
D) placing it under a bright light for 24 hours

Question 10

What is one main effect of auxins on plant growth?

Accepted Answer

A) They reduce growth by inhibiting cell division. 
B) They increase growth by promoting cell elongation. 
C) They increase growth by increasing the rate of photosynthesis. 
D) Auxins have no effect on plant growth. 
A) They reduce growth by inhibiting cell division. 
B) They increase growth by promoting cell elongation. 
C) They increase growth by increasing the rate of photosynthesis. 
D) Auxins have no effect on plant growth.

Question 11

In leaf abscission, the abscission layer forms where the

Accepted Answer

A) leaf stalk joins the stem. 
B) axillary bud joins the stem. 
C) root joins the stem. 
D) leaf stalk joins the leaf. 
A) leaf stalk joins the stem. 
B) axillary bud joins the stem. 
C) root joins the stem. 
D) leaf stalk joins the leaf.

Question 12

Fruit that forms on an unpollinated plant in response to a hormone will lack

Accepted Answer

A) flavor. 
B) seeds. 
C) rind. 
D) naturally occurring hormones. 
A) flavor. 
B) seeds. 
C) rind. 
D) naturally occurring hormones.

Question 13

Plant hormones

Accepted Answer

A) must be produced in large quantities to be effective. 
B) act on all cells they encounter. 
C) are chemical signals that influence growth and development. 
D) are rare and produced only in response to stress. 
A) must be produced in large quantities to be effective. 
B) act on all cells they encounter. 
C) are chemical signals that influence growth and development. 
D) are rare and produced only in response to stress.

Question 14

When a nursery worker pinches off the terminal buds on a young chrysanthemum plant to make it grow bushy, which of the following plant hormones is mainly responsible for growth of side branches?

Accepted Answer

A) an auxin 
B) a gibberellin 
C) a cytokinin 
D) abscisic acid 
A) an auxin 
B) a gibberellin 
C) a cytokinin 
D) abscisic acid

Question 15

-Which of the following statements is supported by this figure?

Accepted Answer

A) The greater the concentration of auxin, the more promotion of root elongation occurs. 
B) Auxin concentrations below 10⁻⁸ g/L promote both root and stem elongation. 
C) Auxin concentrations around 10⁻⁴ g/L promote stem elongation but inhibit root elongation. 
D) Auxin concentrations above 0.9 g/L are best for promoting stem elongation. 
A) The greater the concentration of auxin, the more promotion of root elongation occurs. 
B) Auxin concentrations below 10⁻⁸ g/L promote both root and stem elongation. 
C) Auxin concentrations around 10⁻⁴ g/L promote stem elongation but inhibit root elongation. 
D) Auxin concentrations above 0.9 g/L are best for promoting stem elongation.

Question 16

A plant will only flower if the night length is longer than 14 hours. This plant is a

Accepted Answer

A) long-day plant. 
B) short-night plant. 
C) short-day plant. 
D) day-neutral plant. 
A) long-day plant. 
B) short-night plant. 
C) short-day plant. 
D) day-neutral plant.

Question 17

Which hormone prevents a seed released in the fall from germinating immediately?

Accepted Answer

A) auxins 
B) abscisic acid 
C) gibberellins 
D) ethylene 
A) auxins 
B) abscisic acid 
C) gibberellins 
D) ethylene

Question 18

-In addition to demonstrating that auxin stimulates elongation, this diagram also shows that

Accepted Answer

A) application of additional auxin causes greater bending. 
B) the application of auxin causes growth. 
C) removing shoot tips also removes auxin receptors. 
D) the lower parts of the hoot are able to detect light. 
A) application of additional auxin causes greater bending. 
B) the application of auxin causes growth. 
C) removing shoot tips also removes auxin receptors. 
D) the lower parts of the hoot are able to detect light.

Question 19

Which of the following is an example of an evolutionary adaptation that decreases herbivory?

Accepted Answer

A) Plants of the milkweed family produce a toxin that Monarch butterflies can store in their bodies. 
B) Corn plants attacked by herbivores release an airborne chemical that turns on defensive genes in nearby corn plants. 
C) Caterpillars that feed on plants tend to be green. 
D) Damaged, partially eaten leaves can seal off the damaged area by hardening cell walls. 
A) Plants of the milkweed family produce a toxin that Monarch butterflies can store in their bodies. 
B) Corn plants attacked by herbivores release an airborne chemical that turns on defensive genes in nearby corn plants. 
C) Caterpillars that feed on plants tend to be green. 
D) Damaged, partially eaten leaves can seal off the damaged area by hardening cell walls.

Question 20

Grass shoots bend toward the light because, on the shadowed side, a(n)

Accepted Answer

A) reduction in auxin levels promotes cell elongation. 
B) reduction in auxin levels prevents cell elongation. 
C) increase in auxin levels promotes cell elongation. 
D) increase in auxin levels promotes cell division. 
A) reduction in auxin levels promotes cell elongation. 
B) reduction in auxin levels prevents cell elongation. 
C) increase in auxin levels promotes cell elongation. 
D) increase in auxin levels promotes cell division.

Exam 33: Control Systems in Plants

Which of the following is the factor that initiates flowering in long-day plants?

How does phytochrome control flowering?

The event that triggers fruit formation is the growth of a pollen tube through the carpel of a flower. Which of the following is a reasonable hypothesis about the basis of this effect?

Which of the following is a way that plants use animals as a defense against herbivores?

Which type of plant hormone generally acts as a growth inhibitor?

The plant growth response to touch is known as

In plant research labs, plants are often grown in light-proof chambers where the hours of light and dark are carefully controlled. A new researcher goes into a chamber and accidentally turns on the light during the "dark" period. What is likely to happen?

-If you cut off the top of a carrot and place it in water to see if you can get it to grow new roots, you should add

Which of the following is a good way to ripen a green, unripe fruit?

What is one main effect of auxins on plant growth?

In leaf abscission, the abscission layer forms where the

Fruit that forms on an unpollinated plant in response to a hormone will lack

Plant hormones

When a nursery worker pinches off the terminal buds on a young chrysanthemum plant to make it grow bushy, which of the following plant hormones is mainly responsible for growth of side branches?

-Which of the following statements is supported by this figure?

A plant will only flower if the night length is longer than 14 hours. This plant is a

Which hormone prevents a seed released in the fall from germinating immediately?

-In addition to demonstrating that auxin stimulates elongation, this diagram also shows that

Which of the following is an example of an evolutionary adaptation that decreases herbivory?

Grass shoots bend toward the light because, on the shadowed side, a(n)

Biology: Exploring Life

The Chemical Basis of Life

The Molecules of Cells

A Tour of the Cell

The Working Cell

How Cells Harvest Chemical Energy

Photosynthesis: Using Light to Make Food

The Cellular Basis of Reproduction and Inheritance

Patterns of Inheritance

Molecular Biology of the Gene

How Genes Are Controlled

DNA Technology and Genomics

How Populations Evolve

The Origin of Species

Tracing Evolutionary History

Microbial Life: Prokaryotes and Protists

The Evolution of Plant and Fungal Diversity

The Evolution of Invertebrate Diversity

The Evolution of Vertebrate Diversity

Unifying Concepts of Animal Structure and Function

Nutrition and Digestion

Gas Exchange

Circulation

the Immune System

Control of Body Temperature and Water Balance

Hormones and the Endocrine System

Reproduction and Embryonic Development

Nervous Systems

the Senses

How Animals Move

Plant Structure, Growth, and Reproduction

Plant Nutrition and Transport

the Biosphere: an Introduction to Earths Diverse Environments

Behavioral Adaptations to the Environment

Population Ecology

Communities and Ecosystems

Conservation Biology

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