Life: The Science of Biology

David E. Sadava, David M. Hilliss, H. Craig Heller,May Berenbaum

Chapter 37

Regulation of Plant Growth - all with Video Answers

Educators

Chapter Questions

Problem 1

Which of the following is not an advantage of seed dormancy?
$a .$ It makes the seed more likely to be digested by birds that disperse it.
$b$. It counters the effects of year-to-year variations in the environment.
c. It increases the likelihood that a seed will germinate in the right place.
d. It favors dispersal of the seed.
$e .$ It may result in germination at a favorable time of year.

Sara Ross

Sara Ross

Numerade Educator

Problem 2

Which of the following does not occur in seed germination?
$a .$ Imbibition of water
$b .$ Metabolic changes
c. Growth of the radicle
$d .$ Mobilization of nutrient reserves
e. Extensive mitotic divisions

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 3

To mobilize its nutrient reserves, a germinating barley seed
$a .$ becomes dormant.
$b .$ undergoes senescence.
c. secretes gibberellins into its endosperm.
$d$. converts glycerol and fatty acids into lipids.
$e .$ takes up proteins from the endosperm.

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 4

The gibberellins
$a$. are responsible for phototropism and gravitropism.
$b$. are gases at room temperature.
$c .$ are produced only by fungi.
$d .$ cause flowering in plants.
$e .$ inhibit the synthesis of digestive enzymes by barley seeds.

Sara Ross

Numerade Educator

Problem 5

In coleoptile tissue, auxin
$a .$ is transported from base to tip.
$b$. is transported from tip to base.
c. can be transported toward either the tip or the base, depending on the orientation of the coleoptile with respect to gravity.
$d$. is transported by simple diffusion, with no preferred direction.
$e .$ is not transported, because auxin is used where it is made.

Sara Ross

Numerade Educator

Problem 6

Which process is not directly affected by auxin?
a. Apical dominance
b. Leaf abscission
$c .$ Synthesis of digestive enzymes by barley seeds
$d$. Root initiation
$e .$ Cell elongation

Shazia Naz

Numerade Educator

Problem 7

Signal transduction for both auxin and gibberellins involves
a. binding of the hormone to a nuclear receptor.
$b$. degradation of a repressor of gene transcription.
c. production of a small molecule second messenger.
$d$. iight absorption followed by chemical changes.
$e .$ breakdown of the hormone.

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 8

Which statement about cytokinins is not true?
a. They promote cell division in tissue cultures.
b. They delay the senescence of leaves.
c. They usually promote the elongation of stems.
d. They act by a receptor with protein kinase activity.
$e .$ They were discovered as a breakdown product of DNA.

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 9

Ethylene
$a$. causes the triple response in seedlings growing underground.
$b$. is liquid at room temperature.
$c .$ delays the ripening of fruits.
$d$. generally promotes stem elongation.
e. inhibits the swelling of stems, in opposition to cytokinin's effects.

Sara Ross

Numerade Educator

Problem 10

Phytochrome
$a$. is the only photoreceptor pigment in plants.
$b$. exists in two forms interconvertible by light.
$c .$ is a pigment that is colored red or far-red.
$d$. is a green-light receptor.
$e .$ is the photoreceptor for phototropism in coleoptiles.

Sara Ross

Numerade Educator