2. photoperiodism

Question 1

short day plants

Answer 1

winter - flower when the photoperiod is less than the critical length

Question 2

long day plants

Answer 2

summer - flower when the photoperiod is longer than the critical length

Question 3

day neutral

Answer 3

unaffected by the amount of light per day and flower any time of the year

Question 4

photoperiodism

Answer 4

the regulation of seasonal activities of plants based on the day length (photoperiod)

Question 5

how do plants activate the photoperiod response?

Answer 5

it is controlled by the pigment photochrome

Question 6

adaptive advantages of photoperiodism (3 examples)

Answer 6

1. seeds germinate at the time of the year when they have the highest chance of survival
2. seed masting can occur to increase survival as not all seeds eaten
3. flower when pollinators are active to cross pollinate = inc in genetic variation

Question 7

when do short-day plants flower?

Answer 7

when Pr accumulates at night (Pr conc higher than Pfr conc)

Question 8

when do long-day plants flower?

Answer 8

when Pfr accumulates during the day (Pfr conc higher than Pr conc)

Question 9

What is Pr?

Answer 9

red light common in the day (665nm wavelength)

Question 10

What is Pfr?

Answer 10

far red light common at night (725nm wavelength)

Question 11

Describe the phytochrome system

Answer 11

in day Pr into Pfr. in night Pfr into Pr.