F ... 25 - External Factors and Plant Growth Flashcards Preview

Plant Biology > F ... 25 - External Factors and Plant Growth > Flashcards

Flashcards in F ... 25 - External Factors and Plant Growth Deck (17)
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1
Q

external factors?

A

gravity
light
touch

2
Q

tropism

A

directional growth in response to external stimulus

3
Q

gravitropism

A

directional growth due to gravity… bending

[ plant’s knocked over ]

4
Q

thigmotropism

A

directional growth due to touch… tendrils
[ plant touches object ]
can inhibit growth - elongation

5
Q

phototropism

A

directional growth due to light

6
Q

morphogenesis

A

change in dev or growth in response to stimulus

7
Q

gravity perception in plants

A

starch statoliths settle, redistributes auxin, change in growth

8
Q

how is light perceived as a signal?

A

phytochromes
phototropisms
photomorphogenesis
circadian rhythms

9
Q

phytochrome

A

photoreceptor… red / far red light

10
Q

phototropism

A

shoots + (towards light)

roots - (away from light)

11
Q

photomorphogenesis

A

development affected by light

12
Q

circadian rhythms

A

cyclic responses to enviro stimuli (~24 hours)

leaf rises / lowers

13
Q

photoperiodism

A

flowering time

physiological resp to photoperiod (day/night lengths)

14
Q

short day plant

A

req light period shorter than critical daylength to flower

15
Q

long day plant

A

req light period longer than # hours to flower

16
Q

day-neutral plant

A

unaffeted by photoperiodism… flowers at maturity

17
Q

heliotropism

A

solar tracking [sunflowers]

NOT asymmetric growth, mvt of connective tissue at organ base