Sensory Systems in Plants-Chapter 40

Question 1

a plant moves by ______________

Answer 1

nonphotosynthetic pigments detecting light and mediating the plant’s response to it

Question 2

general light triggered development

Answer 2

photomorphogenesis

Question 3

directional growth responses to light

Answer 3

phototropisms

Question 4

a pigment containing protein that consists of 2 parts

Answer 4

phytochrome

Question 5

a process that tells the cell to create new proteins or stop making proteins

Answer 5

signal-transduction pathway

Question 6

part of a phytochrome that is light receptive

Answer 6

chromophore

Question 7

initiates the signal transduction pathway

Answer 7

apoprotein

Question 8

Pr abrorbs _________ light at _________nm. This wavelength is found in sunlight

Answer 8

red at 660

Question 9

Pfr absorbs __________ light at 730nm. This wavelength is found more in reflected light

Answer 9

far-red at 730

Question 10

when Pr absorbs red light, it converts it to Pfr (active form), this causes genes to be _________

Answer 10

transcribed

Question 11

when Pfr absorbs far red light, it converts it to Pf (inactive form), lots of red light equals lots of _____

Answer 11

Pfr

Question 12

Pfr enters the _______, binds to transcription factors leading to expression of light regulated genes

Answer 12

nucleus

Question 13

inhibited by far red light and stimulated by red light

Answer 13

seed germination

Question 14

a lack of red light and shoots elongation

Answer 14

shoot elongation

Question 15

crowded plants receive far red light bounced from neighboring plants and increase their height

Answer 15

detection of plant spacing

Question 16

bending of growing stems to sources of light with _______ wavelengths (460nm)

Answer 16

blue

Question 17

PHOT1 is a blue light receptor that stimulates the kinase region of PHOT1 to autophosphorylate and triggers a __________

Answer 17

signal transduction

Question 18

the response of a plant to the gravitational field of the Earth

Answer 18

gravitropism

Question 19

shoots exhibit ________ gravitropism

Answer 19

negative

Question 20

roots exhibit __________ gravitropism

Answer 20

positive

Question 21

gravity is sensed in the endodermal cells, signaling structures are __________ that sink in cytoplasm

Answer 21

amyloplasts

Question 22

accumulates on the lower side of stem due to amyloplast position , results in asymettrical cell elongation and curvature of stem upward

Answer 22

auxin

Question 23

in roots, the _____ is the site of gravity perception, cells closer to gravity grow less

Answer 23

cap

Question 24

permanent response to a mechanical stress

Answer 24

thigmomorphogenesis

Question 25

directional response to a mechanical stress

Answer 25

thigmotropism

Question 26

touch induced plant movements involve reversible changes in _________, cells that are involved are ________ cells, movements can be towards the sun to maximize photosynthesis

Answer 26

turgor pressure

pulvini

Question 27

dormancy results in cessation of growth during unfavorable conditions, results in __________ which is the dropping of leaves (advantage because if conserves resources)

Answer 27

abscission

Question 28

changes occur at the _____________ at the petiole’s base, differentiation between the protective layer (stays) and the separation layer (removed)

Answer 28

abscission zone

Question 29

How do plants respond to cold temperatures?

Answer 29

(1) increased number of lipids in plasma membrane
(2) production of antifreeze proteins

*some plants can undergo deep supercooling and survive temps of -40C

Question 30

plants produce _____________ is exposed to rapid temperature increases

Answer 30

heat shock proteints

Question 31

plants can survive otherwise lethal temperatures if they are gradually exposed to increasing temperatures

Answer 31

thermotolerance

Question 32

chemicals produced in one part of an organism and transported to another part where they exert a response (no glands in a plant)

Answer 32

hormones

Question 33

_____________ preformed the auxin experiment by changing light entry with various caps

Answer 33

Charles and Francis Darwin

Question 34

auxin was given its name by ___________

Answer 34

Frits Went

Question 35

How does auxin work?

Answer 35

increases plant plasticity of the plant cell wall, produced on the lit tip on the plant, migrates to the opposite side, causes elongation of these cells and the plant bends

Question 36

the _______________ provides a model linking auxin to cell wall expansion

Answer 36

acid growth hypothesis

Question 37

produced at the shoot apical meristems and developing fruits, stimulate cell division and differentiation, promote the growth of later buds into branches

Answer 37

cytokinins

Question 38

the plant pathogen Agrobacterium introduces genes into the palnt genome that increase the production of cytokinin and auxin. what does this cause?

Answer 38

massive cell division and formation of a crown gall tumor

Question 39

over 100 naturally occuring plant hormones, have important effects on stem elongation, restores normal growth, hasten seed germination, used commercially to extend internode length in grapes

Answer 39

gibberellins

Question 40

a gas that retards growth in plants, suppresses stem and root elongation, controls leaf, flower and fruit abscission, hastens fruit ripening

Answer 40

ethylene

Question 41

synthesized mainly in matures green leaves, fruits, and root caps, introduces formation of dormant winter buds, counteracts gibberellins and auxin, suppresses bud growth, also helps to regulate stomata and is necessary for dormancy in plants

Answer 41

abscisic acid