What happens immediately after a phytochrome is activated by light?

A certain short-day plant flowers only when days are less than 12 hours long. Which of the following would cause it to flower?a. a 9-hour night and 15-hour day with 1 minute of darkness after 7 hoursb. an 8-hour day and 16-hour night with a flash of white light after 8 hoursc. a 13-hour night and 11-hour day with 1 minute of darkness after 6 hoursd. a 12-hour day and 12-hour night with a flash of red light after 6 hours

A plant nursery manager tells the new night security guard to stay out of a room where chrysanthemums (which are short-day plants) are about to flower. Around midnight, the guard accidentally opens the door to the chrysanthemum room and turns on the lights for a moment. How might this affect the chrysanthemums? How could the guard correct the mistake?

SCIENTIFIC THINKING The discovery of auxin is a good example of how scientists build upon each other's work. For each of the three sets of researchers discussed in the chapter (the Darwins, Boyle-Jensen, and Went), write a one-sentence summary of what they discovered. If you were going to credit one person as being the 'discoverer' of auxin, who would it be?

A conformational change in a substance called phytochrome __________.

You are interested in determining what part of a plant senses the light, which leads to phototropism. A good first experiment would be to __________.

Some seeds require light for germination. This process is controlled by the phytochrome system. Which of the following germination treatments would inhibit germination of such seeds?

Photoperiodism is __________.

An Alaskan trapper worried about being attacked by grizzly bears left the lights on in his cabin all the time. Plants just outside the cabin flowered a month early. Which of the following best explains this?