Exam 36: Regulation of Plant Growth

Refer to the figure below showing the changes that occur when a leaf is about to fall from the stem. A decrease in auxin in which region of the diagram would result in formation of the abscission zone?

In the experiments of Charles and Francis Darwin, which parts of the seedlings were shown to be sensitive to light?

A germinating grass seedling embryo produces gibberellins, which can signal the plant to mobilize stored _______.

Phytochromes

Signals such as hormones or different colors of light, which control the life of a plant, usually act by altering

After a few days, a houseplant that has been accidentally knocked on its side will produce shoots that are growing upward relative to its new position.This phenomenon is called

Which statement about the dormancy of seeds is false?

The role of the hormone called _______ in phototropism was first indicated in studies carried out by Charles Darwin and his son, Francis.

Unlike other plant hormones, ethylene

The semi-dwarf wheat and rice plants that led to the Green Revolution described in the chapter opening have mutations in the signal transduction pathway for gibberellins.You wish to use genetic engineering to make corn plants that are semi-dwarf.Besides short stature, what other effects would you expect to see in the signal transduction mutant strain? How would you use other hormones to overcome them?

Arabidopsis opens its stomata during the day and closes them at night.This _______ could be disrupted experimentally by changing the daylight cycle to fool the plant.

Darwin studied the plant response called _______ by "blindfolding" the coleoptiles of monocot seedlings.

The major reason why some fruits are packaged in bags made of a plastic that is permeable to gases is to

Gibberellins are antagonized by the hormone known as

Based on your knowledge of the effects of cytokinins on plant growth and development, which of the following is the most likely phenotype of a plant that has been bioengineered to have elevated cytokinin synthesis? (Assume that the levels of other plant hormones are normal.)

Arabidopsis open their stomata during the day and close them at night.This response is an example of a(n) _______.

The effect of phytochrome begins with _______ light being absorbed and later involves a(n) _______ binding to DNA.

Auxin's polar transport relies in part on the fact that auxin is a weak acid that

Which statement does not describe an effect of auxin?

A researcher who wishes to experimentally manipulate leaf senescence in tobacco would apply _______ to promote senescence and _______ to delay it.