?

AP® Biology

Free Version

Upgrade subject to access all content

Difficult

Molecular Signal for Blooming

APBIO-BEJIGE

Chrysanthemums are naturally short-day plants that flower and bloom with the long nights of fall or winter when there is limited exposure to red light. Such conditions make the conversion of $P_FR$ to $P_R$ favorable. In turn, the accumulation of $P_R$ plays a role in the bloom signal.

Based on the model shown below, which of the following describes how might it be possible to make chrysanthemums bloom during the summer months when the days are longer?

Created for Albert.io. Copyright 2016. All rights reserved.

A

Cover the chrysanthemums for at least six hours a day for a couple weeks.

B

Expose the plants with artificial daylight for an hour in the middle of the dark period for a couple of weeks.

C

It is not possible to alter the program of gene expression by altering environmental conditions.

D

Cover the chrysanthemums for at least 12 hours a day for a couple weeks.