Chapter 27

Home gardeners commonly pinch off the shoot tips of certain plants in order to promote fuller, bushier growth. Explain why removal of the shoot tip should promote such growth.

What is meant by parthenocarpic fruit? Which two plant hormones are used to produce such fruit?

Compare and/or contrast auxins and cytokinins in each of the following: principal sites of biosynthesis; polarity of transport; cell types or tissues involved in transport; effect on cell division; effect on the production of roots and shoots in tissue cultures.

Explain how abscisic acid regulates the opening and closing of stomata.