BIO 116 EXAM 3 TEST PAPER COMPLETE
SOLUTIONS AND ACCURATE RESPONSES
●● Plants receive signals from the environment & respond by ______.
Answer: altering growth & development
●● Any response resulting in a curvature of organs toward or away from
a stimulus is called a ______.
Answer: tropism
●● Response to light; mediated by the hormone auxin
Answer: Phototropism
●● Shoots show ______ phototropism, roots show _____.
Answer: positive; negative
●● Response to gravity; mediated by the hormone auxin as well as in
some plants detection of gravity occurs by the settling of statoliths
Answer: Gravitropism
●● Dense cytoplasmic components
Answer: statoliths
,●● Shoots show _____ gravitropism, roots show ________.
Answer: negative; positive
●● Response to touch (rapid leaf movements in response to mechanical
stimulation/disturbance)
Ex. Mimosa pudica
Answer: Thigmotropism
●● Transmission of electrical impulses that cause a touch response
Answer: Action potentials
●● When electrical potential reaches motor cells at the base of the
leaflet, the folding is caused by a _________ out of motor cells
Answer: rapid efflux of potassium followed by rapid water transport
●● effects of light on plant morphology
Answer: photomorphogenesis
●● 2 major classes of light receptors that mediate photomorphogenesis
Answer: blue-light photoreceptors & phytochrome (for red & far-red
lights)
,●● Morphological adaptations for growing in darkness
Answer: Etiolation
●● Changes in which shoots and roots then begin to grow normally
Answer: De-etiolation
●● 4 Phytochrome responses
Answer: De-etiolation, seed germination, shade avoidance, & control of
biological clock
●● Phytochromes exist in 2 photoreversible states with a conversation of
_____ to ____ triggering many developmental responses
Answer: P(r) to P(fr)
●● A naturally occurring organic molecule that is synthesized in one part
of the organism and has an effect on another part of the organism
Answer: Hormone
●● In a plant cell, most hormones can also have significant effects in
_______ where they are synthesized
Answer: the same cells
, ●● Plant hormones are ______ that modify or control one or more
specific physiological processes within a plant
Answer: chemical signals
●● Plant hormones help coordinate: (3 things)
Answer: growth, development,& responses to stimuli
●● Are plant hormones produced in low or high concentrations?
Answer: Low concentrations
●● Each hormone has multiple effects, but _______
Answer: multiple hormones can influence a single process
●● What do plant responses depend on?
Answer: The amount & concentration of specific hormones and often
the combination of hormones present
●● Any chemical that promotes elongation of shoot tip
Answer: Auxin
●● One of the common naturally occurring auxins in plants
Answer: Indoleacetic acid
SOLUTIONS AND ACCURATE RESPONSES
●● Plants receive signals from the environment & respond by ______.
Answer: altering growth & development
●● Any response resulting in a curvature of organs toward or away from
a stimulus is called a ______.
Answer: tropism
●● Response to light; mediated by the hormone auxin
Answer: Phototropism
●● Shoots show ______ phototropism, roots show _____.
Answer: positive; negative
●● Response to gravity; mediated by the hormone auxin as well as in
some plants detection of gravity occurs by the settling of statoliths
Answer: Gravitropism
●● Dense cytoplasmic components
Answer: statoliths
,●● Shoots show _____ gravitropism, roots show ________.
Answer: negative; positive
●● Response to touch (rapid leaf movements in response to mechanical
stimulation/disturbance)
Ex. Mimosa pudica
Answer: Thigmotropism
●● Transmission of electrical impulses that cause a touch response
Answer: Action potentials
●● When electrical potential reaches motor cells at the base of the
leaflet, the folding is caused by a _________ out of motor cells
Answer: rapid efflux of potassium followed by rapid water transport
●● effects of light on plant morphology
Answer: photomorphogenesis
●● 2 major classes of light receptors that mediate photomorphogenesis
Answer: blue-light photoreceptors & phytochrome (for red & far-red
lights)
,●● Morphological adaptations for growing in darkness
Answer: Etiolation
●● Changes in which shoots and roots then begin to grow normally
Answer: De-etiolation
●● 4 Phytochrome responses
Answer: De-etiolation, seed germination, shade avoidance, & control of
biological clock
●● Phytochromes exist in 2 photoreversible states with a conversation of
_____ to ____ triggering many developmental responses
Answer: P(r) to P(fr)
●● A naturally occurring organic molecule that is synthesized in one part
of the organism and has an effect on another part of the organism
Answer: Hormone
●● In a plant cell, most hormones can also have significant effects in
_______ where they are synthesized
Answer: the same cells
, ●● Plant hormones are ______ that modify or control one or more
specific physiological processes within a plant
Answer: chemical signals
●● Plant hormones help coordinate: (3 things)
Answer: growth, development,& responses to stimuli
●● Are plant hormones produced in low or high concentrations?
Answer: Low concentrations
●● Each hormone has multiple effects, but _______
Answer: multiple hormones can influence a single process
●● What do plant responses depend on?
Answer: The amount & concentration of specific hormones and often
the combination of hormones present
●● Any chemical that promotes elongation of shoot tip
Answer: Auxin
●● One of the common naturally occurring auxins in plants
Answer: Indoleacetic acid
