The Sensory system in plants Flashcards
Why plants are simpler and slower?
no receptors
defined as any external and internal changes in the environment that cause a response
stimulus
A process where light is necessary. Plants produce food through this
photosynthesis
a term used for non-directional development responses of plants to light
photomorphogenesis
The result of photomorphogenesis
changes in form or flowering
Which is a directional plant growth response.
phototropism
a pigment -containing protein, is present in plants, as well as in green algae.
Phytochrome
Phytochrome exists in two convertible forms:
Pr (phytochrome red) and pfr (phytochrome far red)
shading in plants result in an increase in far red light compared to red light
Plant Spacing
directional response due to a directional stimulus like light
Phototropism
inhibited by far red (Pr) light and stimulated by red (Pr) light in many plants.
Seed Germination
results in etiolation is explained by the absence of red light.
Shoot Elongation
This response of plants to gravitational force
gravitropism
is shown in the response of makahiya (Mimosa pudica) to touch
Thigmonasty
When touched, there are changes that happen in the turgor pressure at the base of each pulvinus cell
Thigmonasty
show long, weak stems, and smaller leaves due to longer internodes.
Etiolated plants
A directional growth response of a plant or a plant part in response to a contact with an object like fence, wire, plant, or animal
Thigmotropism
Example of Thigmotropism
Twining plant’s tendril
This change in turgor pressure causes the leaflets to
close or fold
sinks towards the center of gravity
Amyloplasts
what do you call a negative to positive response?
Bravitropic response
Plant response in Mechanical stimuli
- turgor pressure cause to close or fold
- ions move outer
3.rapid water transport (out cells) - 15-30mins regain turgidity reversible response
Plant responses are not limited to growth responses.
Temperature
adaptive measure in plants when environmental conditions are not favorable.
Seed dormancy
stay dormant for hundreds of years
Seed dormancy
in plants, the process by which leaves are shed is called
abscission
Shedding of leaves help plants
conserve water and energy and withstand cold temperature
forms that proceeds downwards until the leaf is separated from the stem
Tear line
prevent water loss and to prevent the invasion
protective covering
is formed between the stem and the base of the pertriole of the leaf
abscission layer (this also swell)
responsible for the formation of the abscission layer
abscisic acid
