Chapter 38 Sensory In Plants

Front 1

this is a growth response involving the movement (bending or curving) of a plant part in response to an external stimulus

Back 1

tropism

Front 2

movement of plant toward the stimulus is what type of tropism?

Back 2

positive

Front 3

movement of plant away from the stimulus is what type of tropism?

Back 3

negative

Front 4

growth in response to directional light

Back 4

phototropism

Front 5

when shoot tip grows toward the light source the plant is exhibiting what kind of phototropism?

Back 5

positive

Front 6

a light absorbing substance

Back 6

pigment

Front 7

the main photosynthetic pigment, occurs in all photosynthetic eukaryotes and cyanobacteria

Back 7

chlorophyll a

Front 8

these pigments are not directly involved in photosynthesis and they transfer captured light energy to chlorophyll a

Back 8

accessory pigments

Front 9

an accessory pigment in plats, green algae, and euglenoids

Back 9

chlorophyll b

Front 10

accessory pigments that are lipid soluble and are present in chloroplasts

Back 10

caretenoids

Front 11

accessory pigment that protects chlorophyll molecules from light damage

Back 11

anti-oxidant

Front 12

these three colors are masked by chlorophyll

Back 12

red, yellow, orange

Front 13

at 430,662 nm (blue, red) what pigment is absorbed?

Back 13

chlorophyll a

Front 14

at 480,642 nm (blue, red) what pigment is absorbed?

Back 14

chlorophyll b

Front 15

at 460,500 nm (blue, green) what pigment is absorbed?

Back 15

caretenoids

Front 16

the maximum rates of photosynthesis correspond to absorption spectrum of what photosynthetic pigment?

Back 16

chlorophyll a

Front 17

plants are very sensitive to this type of light because it is not strongly absorbed by photosynthetic pigments and it acts as signal about local environments because it passes through leaves and indicates shade

Back 17

far red light

Front 18

species adapted to high light habitats elongate their stems in what kind of light conditions?

Back 18

low light conditions

Front 19

plants grow toward what color light?

Back 19

blue

Front 20

what two colors drive photosynthesis?

Back 20

red and blue

Front 21

what kind of light will cause plants adapted to high light habitats to elongate their stems, plants that are being shaded

Back 21

far red

Front 22

the response by an organism to relative lengths of day and night

Back 22

photoperiodism

Front 23

what is the significance of photoperiodim? (3)

Back 23

1. allow plants to respond to seasonal changes in climate
2. synchronize flowering with pollinator availability
3. trigger seed germination

Front 24

category of photoperiodism that flower only when days are longer than a critical period; usually in midsummer (long days and short nights )

Back 24

long day

Front 25

category of photoperiodism that flower only when days are shorter than a critical period, spring, late summer, or fall (short days, long nights)

Back 25

short day

Front 26

category of photoperiodism wher ethe flower irrespective of photoperiod (day length has no effect)

Back 26

day neutral

Front 27

why do plants respond to night length rather than day length?

Back 27

plants sense light, not dark

Front 28

In what kind of plants will a flash of light trigger flowering?

Back 28

long day plant

Front 29

in what kind of plant with a flash of light prevent flowering?

Back 29

short day plant

Front 30

a pigment that is a specialized light receptor

Back 30

phytochrome

Front 31

there are two conformations(shapes) of phyochrome... what are they

Back 31

one absorbs red light (Pr) and the other absorbs far red light (Pfr)

Front 32

acts as an on-off switch

Back 32

photoreversible

Front 33

hypothesis that states...
1. the phytochrome protein has two distinct conformations
2. the Pr conformation absorbs red light, while the Pfr conformation absorbs far-red light
3. when either form absorbs light, it converts to the other form
4. the Pfr form stimulates germination while the Pr forms inhibits it

Back 33

the photoreversibility hypothesis for phytochrome behavior

Front 34

these type of seeds respond to the last light wavelength they receive

Back 34

lettuce seeds

Front 35

what color light is required to stimulate germination in lettuce seeds?

Back 35

red light

Front 36

this part of the root contributes to the root's response to gravity; gravity sensing cells are located here

Back 36

root cap

Front 37

starch storing organelles that are the primary gravity sensors in plant cells

Back 37

amyloplasts

Front 38

this hypothesis states that some molecules in cells acts as a stimulus receptor

Back 38

statolith hypothesis

Front 39

what part of the cell are amyloplasts found?

Back 39

bottom of cell due to gravity

Front 40

series of events that occur between stimulus and response; usually involves conversion of one type of energy to another

Back 40

signal transduction

Front 41

what are the three types of signal trandsuctions? (types of energy transversions)

Back 41

1. light to chemical
2. mechanical to chemical
3. mechanical to electrical

Front 42

what are two forms of signal transduction from light to chemical? (sunflowers and seedlings)

Back 42

phototropism and heliotropism

Front 43

a type of signal transduction (mechanical -> chemical) effects the response of plants to wind or touch. When plants exhibit touch, what typically happens with their stems?

Back 43

stems remain short and grow thicker

Front 44

a type of signal transduction (mechanical -> chemical) effects the response of plants to wind or touch. When plants DO NOT exhibit touch, what typically happens with their stems?

Back 44

stems elongate, and stay thin

Front 45

this is initiated by contact with a solid object and is caused by uneven rates of growth (an example of mechanical --> chemical energy)

Back 45

coiling of tendrils

Front 46

occurs when proton pumps create a charge separation across the membrane called a membrane voltage and the size of a membrane voltage is a function of the magnitude of charge separations

Back 46

electrical signaling

Front 47

voltage is a form of what kind of energy?

Back 47

potential energy

Front 48

touching two or more of the trigger hairs in the Venus flytrap causes what? (rapid change in membrane voltage)

Back 48

depolarization

Front 49

positive charges rush into the cell "equalizing" charges on either side of the membrane

Back 49

rapid depolarization

Front 50

membrane voltage gradually returns to negative as positive ions move back out

Back 50

repolarization

Front 51

the voltage change that occurs has a characteristic pattern; takes much longer in plants than animals

Back 51

the action potential

Front 52

what springs the trap in venus flytraps?

Back 52

effector cells respond to the action potential by undergoing a rapid change is turgor pressure that moves the leaf and springs trap

Front 53

what type of signal transduction is exhibited when leaves of sensitive plant respond to touch by folding

Back 53

mechanical -> electrical