Detection and Response (CH 40, 42, 43) Flashcards
What is the name of the light sensing protein?
What is this responsible for?
phytochrome
plant growth responses
What are the three plant growth responses?
- ) seed germination
- ) shoot elongation
- ) detection of plant spacing
*look at slide for red light vs. far red light associations
the bending of growing stems to sources of light with blue wavelengths (460-nm range) is associated with what?
phototropin
which cells sense gravity?
endodermal cells
how do plants move?
cell surface proteins, water potential, and plant hormones
What are the 5 plant movements?
Photomorphogenesis Thigmomorphogenesis phototropism thigmotropism gravitrophism
What is Photomorphogenesis?
permanent light-triggered development
What is Thigmomorphogenesis?
permanent touch triggered responses
What is phototropism?
directional growth responses to light
What is Thigmotropism?
directional growth responses to mechanical stimuli
What is Gravitrophisms?
directional growth responses to earth’s gravity
touch induced plant movements involve reversible changes in what?
What is another name for these cells?
turgor pressure
pulvini
What are examples pf touch related turgor?
snapping of the venus flytrap
curling of tendrils
What is an example of a plant that undergoes light related turgor?
bean leaves
what are the two types of gravitropism and give an example
negative = shoots positive = roots
what is responsible for the curvature of stems upwards and asymmetrical cell elongation?
Auxin
what is abscission?
when a plant drops its leaves or petals to conserve resources
True or False:
in plants hormones are produced by specialized tissues?
False
one of the effects of auxin is an increase in__________
plasticity of the plant cell wall
What do cytokinins do?
stimulate cell division and differentiation
there is a plant pathogen called Agrobacterium that introduces genes into the plant genome that increase the production of cytokinins and auxins. What does this cause in the plant?
massive cell division and formation of a crown gall tumor
Whats the name of the 100+ naturally occurring plant hormones?
gibberellins
what do gibberellins do?
hasten seed germination
*used commercially to extend the internode length in grapes resulting in larger grapes
what does ethylene do?
retards growth
- suppresses stem and root elongation
- controls lead, flower, and fruit abscission
- hastens fruit ripening
True or False:
Abscisic Acid counteracts gibberellins and auxin
true
Why is Abscisic Acid important?
2 things
necessary for dormancy in seeds and important in opening and closing the stomata
Animal responses to the environment involve which three systems?
Endocrine, Sensory, Nervous
What do exteroceptors do?
sense external stimuli
ie: smells, taste