Exam 46: Plant Responses to the Environment

What will happen to a long- day plant, such as spinach, if the light- dark pattern is interrupted by a flash of light for several days in a row during the spring?

Cytokinins cause most of their responses in plants by stimulating cell .

Which of these hormones helps plants tolerate drought and cold?

A scientist who claims to have discovered a new plant hormone must demonstrate that this compound is

Which environmental factor is most significant for flowering?

Shoots grow up and roots grow down due to thigmotropism.

The two hormones involved in seed germination and seed dormancy are

What mechanisms do plants use to discourage predation?

triggers the formation of weak- celled abscission layers in leaves and fruits, allowing them to drop off at appropriate times during the year.

When auxin accumulates on the lower side of the shoot of a germinating seed, it

The synthetic herbicide 2,4- D is actually a(n)

Plants, as prey, can't run away from their predators, but they can defend themselves. Is the predatory nature of Venus flytraps a defense mechanism, or does it serve some other purpose?

A Native American tradition uses a "tea" made by soaking willow bark in water as a pain- reliever. Does it work? Why?

What causes the "leaf drop" that occurs in woody plants in preparation for winter dormancy?

plants bloom only when the duration of uninterrupted darkness is shorter than a critical length.

Venus flytraps catch insects in order to supplement their input of

Plants are able to measure the length of the night using the system.

If you were running a tree nursery and wanted to keep your trees dormant until the customer could plant them, which hormone would you spray on the trees?

A species- specific ratio of produced in the apical meristem and _ produced in the root tips maintains a balance between shoot and root growth.

Abscisic acid enforces dormancy of seeds by