Photoreceptors

Question 1

What happens to Pfr and Pr during the day?

Answer 1

More red light that far-red light so Pr absorbs the red lifht causing Pr to be converted into Pfr
Pfr:Pr ratio increases

Question 2

What happens to Pfr and Pr during the night?

Answer 2

Lack of red light causes Pfr to be slowly converted back into Pr

Question 3

Describe short day plants

Answer 3

Length of day is more than 12+ of darkness all Pfr is converted back to Pr
Pfr inhibits flowering in short days plants

Question 4

Describe long day plants

Answer 4

Less than 12hrs of darkeness Pr converted to Pfr

Need a high ratio of Pfr to flower

Question 5

Describe transcription factors

Answer 5

Transcription factors activated and bind to promoter region of a gene
Enables RNA polymerase to attach to gene, all transcription factors collected a transcription initiation complex forms
Gene is turned on

Question 6

Define photoperiod

Answer 6

Environmental cue that determines time of flowering