Deck 37: Plant Signals and Responses to the Environment

Question 1

Darwin's experiments on phototropism illustrated that ____.

A) plant stems bend away from bright lights
B) signals from plant roots control phototropism
C) an opaque cap placed over a shoot tip will cause a plant to bend toward light, but will inhibit growth
D) a translucent cap placed over a shoot tip will cause a plant to bend toward light, but will inhibit growth
E) a translucent cap placed over a shoot tip will cause a plant to both grow and bend toward light

Answer 1

E

Question 2

The most important natural auxin is ____ acid.

A) abscisic
B) gibberellic
C) jasmonic
D) indoleacetic
E) salicylic

Answer 2

D

Question 3

The type of plant hormone primarily responsible for inhibiting leaf abscission is/are ____.

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

Answer 3

E

Question 4

Movement of IAA in a shoot tip is as follows:

A) IAA initially moves downward from the shoot tip via polar transport.
B) IAA initially moves laterally from the shaded to illuminated side of the shoot tip.
C) IAA initially moves laterally from the illuminated to shaded side of the shoot tip.
D) IAA initially moves laterally in the shoot tip via non-polar transport.
E) IAA moves from root tips upwards towards leaves.

Question 5

If you want all of the orange trees in your orchard to uniformly flower and set fruit, you should spray ____ on your plants.

A) brassinosteroids
B) auxins
C) ethylene
D) salicylic acid
E) cytokinins

Question 6

Plant hormones generally ____ concentrations to be effective, and usually have ____ on different plant tissues.

A) are effective only in extremely large; the same effect
B) require only low; different effects
C) require only low; the same effect
D) are effective only in extremely large; different effects
E) require moderate; the same effect

Question 7

The most widely used herbicide in the world, 2,4-D, is a synthetic form of ____.

A) abscisic acid
B) ethylene
C) salicylic acid
D) gibberellin
E) auxin

Question 8

Trimming a shrub will make it become more bushy (have more lateral growth) primarily due to a reduction in the amount of ____.

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

Question 9

An agar block filled with auxin is placed on top of a shoot that has had the shoot tip removed. The agar block is placed so that it covers only one side of the top of the shoot. You would expect the shoot to ____.

A) stop growing
B) grow faster on the side away from the agar block
C) grow straight up
D) grow faster on the side with the agar block
E) grow faster on both the side away from the agar block and on the side with agar block

Question 10

The creosote bush exhibits ____, an adaptation that evolved as a response to their biotic environment.

A) chemical defenses to deter carnivores
B) chemical defenses to deter herbivores
C) drought tolerance
D) high success rates of seed germination
E) low rates of clonal asexual reproduction

Question 11

____ were first discovered in experiments to define the nutrient media required for plant tissue culture.

A) Gibberellins
B) Cytokinins
C) Salicylic acid
D) Auxins
E) Brassinosteroids

Question 12

According to the acid-growth hypothesis, auxin causes increased acidity in cell walls, which then activates ____ that disrupt(s) bonds between cellulose microfibrils, allowing cell expansion.

A) a membrane potential
B) AUX1 transporters
C) proteins called expansins
D) an mRNA
E) K⁺ions

Question 13

The type of plant hormone primarily responsible for inhibiting growth of lateral meristems on shoots and restricting the formation of branches is/are ____.

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

Question 14

Work by Charles Darwin and Francis Darwin was instrumental in the discovery of ____.

A) auxins
B) brassinosteroids
C) jasmonates
D) cytokinins
E) gibberellins

Question 15

If you want to prevent a grass seedling shoot from bending toward light, you should ____.

A) remove the shoot tip
B) place a translucent cap on the shoot tip
C) place an opaque cap on the shoot tip
D) either remove the shoot tip or place a translucent cap on the shoot tip
E) either remove the shoot tip or place an opaque cap on the shoot tip

Question 16

Plant ____ are not known to be influenced by plant hormones.

A) patterns of plant growth
B) cell metabolism
C) gene expression
D) growth responses to light
E) extinction rates

Question 17

The type of plant hormone primarily responsible for promoting the formation of lateral roots is/are ____.

A) jasmonates
B) gibberellins
C) auxins
D) systemin
E) cytokinins

Question 18

Where is the auxin receptor ABP1 located in plant cells?

A) cell wall
B) cytoplasm
C) endoplasmic reticulum
D) plasma membrane
E) nucleus

Question 19

The plant hormone ____ is primarily responsible for the bending of a plant shoot toward light.

A) auxin
B) ethylene
C) systemin
D) salicylic acid
E) brassinosteroid

Question 20

The growth-promoting substance that promotes stem elongation and bending toward light is produced primarily in ____.

A) root tips, traveling to the stem in the xylem
B) the center of the stem region where elongation or bending occurs
C) flowers and flower buds
D) the shoot tip
E) root tips, traveling to the stem in the phloem

Question 21

The plant hormone ____ is primarily responsible for helping break the dormancy of seeds and buds.

A) gibberellin
B) cytokinin
C) ethylene
D) auxin
E) jasmonate

Question 22

Commercial grape growers use ____ to get larger grapes by lengthening the stem on which fruits develop.

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

Question 23

The plant hormone ____ is a gas at normal temperature and pressure.

A) abscisic acid
B) ethylene
C) auxin
D) salicylic acid
E) systemin

Question 24

Plants exude ____ from roots to stimulate the growth of soil fungi.

A) strigolactones
B) cytokinins
C) ethylene
D) auxins
E) jasmonates

Question 25

Placing a ripe apple with other apples that are not ripe will cause the other apples to ripen sooner due to the release of ____.

A) brassinosteroids
B) ethylene
C) auxins
D) oligosaccharins
E) abscisic acid

Question 26

In monoecious species of plants, plants that have separate "male" and "female" flowers both on the same plant, applications of gibberellin ____.

A) cause all flowers formed to be "female"
B) encourage proportionally more "male" flowers to develop
C) cause all flowers formed to actually be both "male" and "female"
D) cause all flowers formed to be "male"
E) encourage proportionally more "female" flowers to develop

Question 27

A pea plant that is not able to make GA₁will ____.

A) grow away from light
B) not be able to make flowers
C) be a dwarf
D) not be able to make fruits
E) have nearly no root growth

Question 28

Synthetic compounds similar to ____ are used to prolong the shelf life of vegetables such as lettuces and mushrooms and to keep cut flowers fresh.

A) salicylic acid
B) jasmonates
C) abscisic acid
D) gibberellins
E) cytokinins

Question 29

Boiling DNA can produce ____.

A) salicylic acid
B) auxins
C) cytokinins
D) abscisic acid
E) jasmonates

Question 30

The plant hormone synthesized mainly in root tips and apparently transported through the plant in xylem sap is ____.

A) gibberellins
B) auxins
C) oligosaccharins
D) ethylene
E) cytokinins

Question 31

The plant hormone ____ causes chloroplasts to mature.

A) cytokinin
B) salicylic acid
C) abscisic acid
D) ethylene
E) gibberellin

Question 32

Suppose you are culturing tobacco callus in a Petri dish at a 10:1 ratio of auxin to cytokinin. To promote only shoot development you would ____.

A) increase the cytokinin ratio
B) increase the auxin ratio
C) reduce the auxin level significantly and increase the cytokinin level slightly
D) grow the tobacco in the dark
E) grow the tobacco in the light

Question 33

Fruit ripening is promoted by ____.

A) ethylene
B) jasmonates
C) gibberellins
D) brassinosteroids
E) abscisic acid

Question 34

The plant hormone structurally similar to adenine is ____.

A) brassinosteroid
B) abscisic acid
C) ethylene
D) cytokinin
E) systemin

Question 35

The plant hormone ____ is apparently synthesized from carotenoid pigments inside plastids.

A) salicylic acid
B) cytokinin
C) abscisic acid
D) jasmonate
E) brassinosteroid

Question 36

The plant hormone ____ governs senescence in plants, such as the loss of leaves in autumn by some plants.

A) cytokinins
B) abscisic acid
C) gibberellins
D) brassinosteroids
E) ethylene

Question 37

Leaf aging is retarded by ____.

A) salicylic acid
B) abscisic acid
C) cytokinins
D) ethylene
E) gibberellins

Question 38

The plant hormones ____ appear to regulate the expression of genes associated with a plant's growth responses to light.

A) salicylic acid
B) brassinosteroids
C) gibberellins
D) jasmonates
E) oligosaccharins

Question 39

The plant hormone ____ is primarily responsible for the growth of a floral stalk in rosette plants such as cabbages.

A) salicylic acid
B) cytokinins
C) ethylene
D) gibberellin
E) brassinosteroid

Question 40

The plant hormone ____ has been shown to both promote pollen tube elongation and inhibit root elongation.

A) jasmonate
B) ethylene
C) brassinosteroid
D) salicylic acid
E) oligosaccharin

Question 41

The plant hormone ____ is generally responsible for long-term inhibition of plant growth such as in buds and seeds.

A) auxin
B) gibberellin
C) oligosaccharin
D) brassinosteroid
E) abscisic acid

Question 42

After a plant has survived a microbial invasion, the rest of the plant is often less vulnerable to future infections. This is called ____.

A) systemic acquired resistance
B) wound defense
C) gene-for-gene recognition
D) hypersensitive response
E) jasmonate response

Question 43

Chaperone-type proteins that stabilize other proteins in response to environmental stresses such as salinity, drought, heat, and cold are ____.

A) systemins
B) phytoalexins
C) PR proteins
D) R genes
E) heat-shock proteins

Question 44

Imagine that you own a nursery and you want to reduce the chance that plants you ship will suffer from shipping damage. You should you apply ____ to the plants before shipping.

A) cytokinins
B) abscisic acid
C) oligosaccharins
D) gibberellins
E) ethylene

Question 45

The plant hormone ____ stimulates stomata to close during a drought.

A) salicylic acid
B) gibberellin
C) abscisic acid
D) auxin
E) oligosaccharin

Question 46

The synthesis of ____ is triggered when cells bind systemin.

A) gibberellin
B) auxin
C) jasmonate
D) cytokinin
E) brassinosteroids

Question 47

Bioactive specialized compounds that function to protect plants from viral, fungal and bacterial pathogens are ____.

A) systemins
B) phytoalexins
C) PR proteins
D) R genes
E) heat-shock proteins

Question 48

The plant signaling molecule ____ is similar in structure to aspirin.

A) abscisic acid
B) ethylene
C) salicylic acid
D) jasmonate
E) oligosaccharin

Question 49

In systemic acquired resistance, the regulatory protein NPR-1 moves from the cytoplasm to the cell nucleus, apparently in response to a buildup of ____ in the cytoplasm.

A) ethylene
B) brassinosteroids
C) oligosaccharins
D) jasmonates
E) salicylic acid

Question 50

In the back and forth evolutionary struggle between plants and virulent bacteria, plants use ____ immunity to combat the bacteria.

A) effector-triggered
B) systemic acquired
C) gene-for-gene
D) hypersensitive
E) jasmonate response

Question 51

The first peptide hormone discovered in plants was ____, which functions in wound response in the tomato.

A) cytokinin
B) systemin
C) gibberellin
D) jasmonate
E) salicylic acid

Question 52

The plant hormone ____ trigger plant responses to environmental stresses such as cold snaps, high salinity, and drought.

A) abscisic acid
B) cytokinin
C) oligosaccharin
D) jasmonate
E) ethylene

Question 53

In some cases, when an insect begins feeding on a leaf the plant responds by activating a signaling pathway that results in the production of ____, which disrupt an insect's capacity to digest proteins.

A) gibberellins
B) lipases
C) chitinases
D) protease inhibitors
E) cytokinins

Question 54

Bioactive specialized compounds are ____.

A) synthesized in some plants as part of basic metabolism
B) only synthesized in plant leaves
C) molecules that attract herbivore pollinators
D) synthesized in floral structures to attract pollinating insects
E) only synthesized in plant roots

Question 55

Researchers have used molecular analysis to determine that ____ evolved after flowering plants, but before eudicots and monocots emerged.

A) auxins
B) cytokinins
C) jasmonates
D) gibbererlins
E) ethylene

Question 56

When a plant has a hypersensitive response, production of ____ triggers effects such as the expression of PR proteins.

A) oligosaccharins
B) salicylic acid
C) ethylene
D) cytokinin
E) brassinosteroids

Question 57

The main stimulus for phototropism is light of ____ wavelengths.

A) red
B) green
C) yellow
D) blue
E) far red

Question 58

Chitinases are examples of ____.

A) systemins
B) phytoalexins
C) PR proteins
D) R genes
E) heat-shock proteins

Question 59

Molecular data has shown that ____ originated during the period when non-bryophytes diverged from the bryophytes.

A) auxins
B) cytokinins
C) jasmonates
D) gibberellins
E) ethylene

Question 60

The second messenger inositol triphosphate (IP₃) appears to be involved in stomatal closure triggered by ____.

A) auxins
B) abscisic acid
C) oligosaccharins
D) salicylic acid
E) gibberellins

Question 62

At night, assuming no artificial lights, primarily ____.

A) P_rabsorbs red light and is converted to P_fr
B) P_rabsorbs far-red light and is converted to P_fr
C) P_frabsorbs red light and is converted to P_r
D) P_frabsorbs far-red light and is converted to P_r
E) P_fris converted to P_r

Question 63

A plant's response to the relative lengths of light and dark periods in its environment during each 24-hour period is a phenomenon called ____.

A) gravitropism
B) photoperiodism
C) thigmotropism
D) circadian rhythms
E) phototropism

Question 65

The plant hormone ____ appears to play a major role in gravitropism in roots and shoots.

A) salicylic acid
B) gibberellin
C) abscisic acid
D) auxin
E) oligosaccharin

Question 66

Flowering in Arabidopsis appears to require ____.

A) production in leaves of CO protein and FT protein
B) movement of CO protein from leaves to the shoot apex
C) expression of CO protein in the shoot apex
D) movement of FT mRNA from leaves to the shoot apex
E) movement of FT protein from leaves to the shoot apex

Question 68

Plant activities that follow a biological clock so that they are based on cycles of about 24 hours are ____.

A) gravitropisms
B) photoperiodisms
C) thigmotropisms
D) circadian rhythms
E) phototropisms

Question 69

Thigmotropism is a growth response to ____.

A) light
B) day length
C) contact with a solid object
D) circadian rhythms
E) gravity

Question 71

You observe a sunflower that moves its leaves so that it tracks the sun across the sky through the day, and a sensitive plant that reversibly folds up its leaflets when you touch it. These are both examples of ____.

A) phototropism
B) thigmotropism
C) stress responses
D) circadian rhythms
E) nastic movements

Question 74

Research by Philip A. Wigge has shown that ____.

A) the genome size of plants varies little between species
B) the genome size of individual plants of the same species is constant
C) FT is important for flowering
D) FT plays no role in flowering
E) the genome size of plants is related to plant size

Question 75

Statoliths, particles that move in the direction gravity pulls them, are typically ____ in plants.

A) amyloplasts
B) calcium carbonate crystals
C) nuclei
D) vacuoles
E) hormones

Question 76

External cues such as increasing day length or warming after a cold snap stimulate gibberellin synthesis, which results in bolting in plants such as cabbages.

Question 77

Which of the following serves as a switching mechanism in the photoperiodic response in plants?

A) phytochrome
B) auxin
C) cryptochrome
D) calmodulin
E) phytoalexin

Question 78

How might a plant communicate to another plant that it has been attacked by a herbivore?

Question 79

During daylight hours, primarily ____.

A) P_rabsorbs red light and is converted to P_fr
B) P_rabsorbs far-red light and is converted to P_fr
C) P_frabsorbs red light and is converted to P_r
D) P_frabsorbs far-red light and is converted to P_r
E) P_fris converted to P_r

Question 80

Typically, ____ does not promote dormancy in perennial plants.

A) dry soil
B) nitrogen deficiency
C) long nights
D) cold nights
E) warm nights