chapter 31 Flashcards
plants rely o n3 types of sensory receptors
- photoresptors
- mechanical receptors
- chemical
tropism
Biological phenomenon indicating growth, bending, or turning of an organism in response to an external signal
phototropism
movement in response to light
movement in response to gravity
gravitropism
movement in respond to the sun
heliotropism
moment in response to temp
thermotropism
movement in response to water
hydrotropism
movement in response to chemicals
chemotropism
movement in response to touch or contact
thigmotropism
tip of plant covered =
no growth towards light
only tip of plant exposed =
growth towards sun
when tip is separated by mica=
no growth towards light
when tip is separated by gelatin
growth towards light
auxin redistributed to _____ side
shaded
high auxin concentration _____rate of cell elongation in root
decrease
high auxin concentration triggers production of ______
ethylene
roots bend away from light
negative respiration
to germinate under shade of another plant is ______
maladaptive
what is the mechanism for light detection
phytochrome
what is phytochrome
a photoreceptor that switch back and forth between two stable forms depending on light exposure
when root caps detect low water condition _____ is produced
aba
_______ slows root elongation by influencing cellulose in celll wall, expanding in diameter rather than length
mechanical perturbations
growth in response to touch or contact
what does mechanical perturbation promote?
synthesis of ethylene which causes cells to expand in diameter and less in length
photoperiodism
Is the effect of day length on flowering
short-day plants flower only when length is less than _____value
critical
long-day plants only flower when when ____ period exceeds a certain length
light
day-neutral plants flower _____ of change in day length
independent
plants should only flower when they are ____enough to support _____of many seeds and ensure that there is enough time for seeds to mature before ____
large, development, winter
the protein ____is synthesized in ___and transported via ____to shoot apical meristem which convert to ____meristems
florigen, leaves, phloem, floral
vernalization
is a prolonged period of exposure to cold temperatures
- it is necessary for some plants to flower
vernalization prevents ____plants from flowering during first ____ or _____plants from flowering during first autumn
long-day, summer, short-day
physical and chemical deterrents (3)
- aerial surveillance
- armed gaurds
sticky traps
plant pathogens
viruses
bacteria
protists
fungi
worms
or other plants
what do plant pathogens cause?
disease and death
which location is the point of entry through viral and bacterial pathogens can infect plant tissues
open stomata
epidermis is ____
line of defence
parasitic plants and some fungi can _______ to weaken epidermal walls
secrete enzymes
some bacteria and fungi _______to prevent stoma to close
secrete chemical
fungi and bacteria secrete enzymes to ____ plant cells walls
degrade
viruses move between cells via ______
plasmodesmata
xylem and phloem also _____ pathogens
transport
bacteria and fungi move through ______
xylem
viruses and bacteria move through?
phloem
biotrophic pathos obtain resources from?
living cells
most biotrophic don’t enter cells, but ____are biotrophic and enter cells to _____
virusis, reproduce
necrotrophic pathogens ______before exploiting/colonizing
kill cells
what do necrotrophic pathogens feed on
compounds that leak from dying or dead cells
parasitic plants
penetrat stems or roots of other plants, tap into hosts plants vascular system
facultative parasitic
if they can’t find a host, they can survive on their own
obligate parasitism
cannot survive on own and needs to find a host
hemiparasitism able to photosynthesis on their own but need?
water and soil nutrients
holoparasitism are not able to photosynthesis and need?
sugar, soil nutrients, water
____overcome host defences and lead to ____
virulent pathogens, disease
____damage only a small part of plant and the host contains the ___
avirulent pathogens, infection
