Exam 4 Flashcards
(20 cards)
__ are chemical signaling molecules that influence physiology and development
hormones
A researcher creates a mutant pea plant in which cytokinins are over expressed and gibberellic acid is under expressed. what is the most likely phenotype of this mutant pea plant?
the pea plant would be shorter with more branches compared to wild-type plants
if a plant stem is exposed to sunlight only on its right side, what happens and why?
the stem will bend to the right as auxin collects on the left side of the plant causing cells to elongate
the orientation of plant growth can respond to gravity because
starch grains within meristem cells are denser than the cytoplasm and move in response to gravity
in lateral growth the __ is the source of new xylem and phloem, whereas the __ renews and maintains the outer layer that protects the stem
vascular cambium; cork cambium
the root apical meristem is covered by a __ that protects the meristem as it grows through the soil
root cap
when a plant releases volatile signals in response to caterpillars this is an example of __
an inducible defense
the dense hairs that cover the leaves of milkweed plants are an example of what defense
mechanical
what plant and/or pathogen proteins are involved in the hypersensitive response?
avirulence (AVR) proteins formed by pathogens & resistance (R) proteins formed by plants
to know if a pop is getter smaller or larger what variables do we need to know?
deaths, emigration, births, immigration
during exponential growth, the number of individuals added per unit time increases, while the __ stays the same
per capita growth rate
logistical growth is __
pop size increases exponentially until it levels off near the K value of the habitat for that species
the role played by a species in its environment is called its:
ecological niche
in general a species’ __ niche will be smaller than its __ niche due to interactions with other organisms in the community
realized; fundamental
Indeterminate growth is the
capability of growth throughout life, continues to branch off
main effects of gibberellic acid
stimulates inner growth
where is the light stimulus sensed in a plant
tip cells
type 1 survivorship
high early survivorship & low survivorship late in life
type 2 survivorship
steady survivorship throughout their lives
type 3 survivorship
low early survivorship & high survivorship after maturity
