Question 1

Recent research on Arabidopsis has shown that florigen is probably ________.

Accepted Answer

A)  a phytochrome molecule that is activated by red light 
B)  a protein that is synthesized in leaves, travels to the shoot apical meristems, and initiates flowering 
C)  a membrane signal that travels through the symplast from leaves to buds 
D)  a second messenger that induces Ca2+ ions to change membrane potential 
E)  a transcription factor that controls the activation of florigen-specific genes 
A)  a phytochrome molecule that is activated by red light 
B)  a protein that is synthesized in leaves, travels to the shoot apical meristems, and initiates flowering 
C)  a membrane signal that travels through the symplast from leaves to buds 
D)  a second messenger that induces Ca2+ ions to change membrane potential 
E)  a transcription factor that controls the activation of florigen-specific genes

Question 2

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)  accumulation of amyloplasts on the lower side of the stem 
C)  gibberellin production by stems 
D)  exposure of phytochrome in the stem to red light 
E)  auxin movement toward the lower side of the stem 
A)  calcium release from the endoplasmic reticulum of shaded cells 
B)  accumulation of amyloplasts on the lower side of the stem 
C)  gibberellin production by stems 
D)  exposure of phytochrome in the stem to red light 
E)  auxin movement toward the lower side of the stem

Question 3

You observe a houseplant on your window sill bending toward the bright afternoon sunlight. Being knowledgeable, you wish to explain the molecular events of the phototropic response to your friend. What is the correct sequence that you would describe?
I. PHOT1 attains a phosphate group and changes shape.
II. Cell elongation occurs on the shady side of the plant.
III. Auxin binds its receptor at target tissues.
IV. Light strikes PHOT1.
V. PHOT1 stimulates downward auxin transport on the shady side of the plant.
VI. Light strikes stomata, which close to minimize water loss.
VII. Cells on the illuminated side of the plant become shorter.

Accepted Answer

A)  VI, VII, II 
B)  VII, II, III, I 
C)  IV, I, V, III, II 
D)  IV, VI, III, VII 
E)  Any of these sequences can initiate phototropism. 
A)  VI, VII, II 
B)  VII, II, III, I 
C)  IV, I, V, III, II 
D)  IV, VI, III, VII 
E)  Any of these sequences can initiate phototropism.

Question 4

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)  Amyloplasts are 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)  Amyloplasts are required for the gravitropic response. 
E)  Cytokinin can only function in the presence of auxin.

Question 5

Plant hormones ________.

Accepted Answer

A)  naturally exist in very large amounts in plants 
B)  change their shape in response to stimulus 
C)  are unable to move from one cell to another 
D)  affect only cells with the appropriate receptor 
A)  naturally exist in very large amounts in plants 
B)  change their shape in response to stimulus 
C)  are unable to move from one cell to another 
D)  affect only cells with the appropriate receptor

Question 6

Which of the following is the strongest evidence that cytokinins regulate cell divisions? There is ________.

Accepted Answer

A)  an increase of cyclin gene expression in tissues exposed to cytokinin 
B)  a decrease of cyclin gene expression in tissues exposed to cytokinin 
C)  induction of shoot growths in tissues exposed to cytokinin 
D)  induction of root growths in tissues exposed to cytokinin 
E)  an ability of cytokinin to interact with auxin at the molecular level and change auxin biosynthesis and transport 
A)  an increase of cyclin gene expression in tissues exposed to cytokinin 
B)  a decrease of cyclin gene expression in tissues exposed to cytokinin 
C)  induction of shoot growths in tissues exposed to cytokinin 
D)  induction of root growths in tissues exposed to cytokinin 
E)  an ability of cytokinin to interact with auxin at the molecular level and change auxin biosynthesis and transport

Question 7

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

Accepted Answer

A)  carotenoid 
B)  xanthophyll 
C)  phytochrome 
D)  chlorophyll 
E)  auxin 
A)  carotenoid 
B)  xanthophyll 
C)  phytochrome 
D)  chlorophyll 
E)  auxin

Question 8

Which of the following is NOT an effect observed in the guard cells of stomata?

Accepted Answer

A)  guard cell shrinkage 
B)  K+ exiting guard cells 
C)  changes in membrane potential 
D)  cell expansion driven by proton ATPases 
E)  water exiting guard cells 
A)  guard cell shrinkage 
B)  K+ exiting guard cells 
C)  changes in membrane potential 
D)  cell expansion driven by proton ATPases 
E)  water exiting guard cells

Exam 37: Plant Sensory Systems, Signals, and Responses

Recent research on Arabidopsis has shown that florigen is probably ________.

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

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

Plant hormones ________.

Which of the following is the strongest evidence that cytokinins regulate cell divisions? There is ________.

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

Which of the following is NOT an effect observed in the guard cells of stomata?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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