Edition by Urry - Chapters 1-56, 9780134478647 | Rationals
Included
All of the following may function in signal transduction in plants except
A.) calcium ions.
B) nonrandom mutations.
C) receptor proteins.
D) phytochrome.
E) second messengers. - ANSWER: B) nonrandom mutations.
In systemic acquired resistance, salicylic acid probably - ANSWER: activates defenses throughout the
plant before infection spreads.
How may a plant respond to severe heat stress? - ANSWER: by producing heat-shock proteins, which
may protect the plantʹs proteins from
denaturing
If a scientist discovers an Arabidopsis mutant that does not store starch in plastids but has
normal gravitropic bending, what aspect of our understanding would need to be
reevaluated? - ANSWER: the role of statoliths in gravitropism
If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would
prevent flowering? - ANSWER: If a long-day plant has a critical night length of 9 hours, which 24-hour
cycle would
prevent flowering?
The chemical signal for flowering could be released earlier than normal in a long-day plant
exposed to flashes of - ANSWER: red light during the night
Which of the following is not a typical component of a signal transduction pathway?
A) production of more signal
B) production of second messengers such as cGMP
C) expression of specific proteins
D) activation of protein kinases
E) phosphorylation of transcription factors - ANSWER: A) production of more signal
Auxin enhances cell elongation in all of these ways except - ANSWER: acidification of the cell wall,
causing denaturation of growth-inhibiting cell wall
proteins.
Charles and Francis Darwin discovered that - ANSWER: light is perceived by the tips of coleoptiles.
Which hormone is incorrectly paired with its function?
A) auxinpromotes stem growth through cell elongation
B) cytokininsinitiate programmed cell death
C) gibberellinsstimulate seed germination
D) abscisic acidpromotes seed dormancy
E) ethyleneinhibits cell elongation - ANSWER: B) cytokininsinitiate programmed cell death
, The hormone that helps plants respond to drought is - ANSWER: abscisic acid.
T/F
Systemic acquired resistance is a generalized plant defense response in organs distant from
the infection site. - ANSWER: TRUE
T/F
Unlike animal hormones, plant hormones are primarily involved in regulating growth and
development. - ANSWER: TRUE
T/F
Plant hormonal control differs from animal hormonal control in that there are no separate
hormone producing organs in plants as there are in animals. - ANSWER: TRUE
T/F
The rapid leaf movements resulting from a response to touch (thigmotropism) involve
transmission of electrical impulses called action potentials. - ANSWER: TRUE
T/F
Roots exhibit negative geotropism whereas stems exhibit positive geotropism. - ANSWER: TRUE
T/F
A long-day plant will flower only when the night is longer than a critical value. - ANSWER: FALSE
T/F
A short-day plant exposed to nights longer than the minimum for flowering but
interrupted by short flashes of light will flower. - ANSWER: TRUE
T/F
The cells of lateral buds are more sensitive to auxin than stem cells. - ANSWER: TRUE
T/F
Experiments on the positive phototropic response of plants indicate that light destroys
auxin. - ANSWER: FALSE
T/F
The detector of light during de-etiolation (greening) of the tomato plant are carotenoid
pigments - ANSWER: FALSE
When an arborist prunes a limb off a valuable tree, he or she usually paints the cut surface.
The primary purpose of the paint is to - ANSWER: block entry of pathogens through the wound.
What is the probable role of salicylic acid in the defense responses of plants? - ANSWER: activate
systemic acquired resistance of plants
A pathogenic fungus invades a plant. What does the infected plant produce in response to
the attack? - ANSWER: phytoalexins