B3.2.7 - Uses Of Plant Hormones

Question 1

What plant hormone does banana give off?

Answer 1

Ethene gas

Question 2

How are plant hormones produced and transported?

Answer 2

They are produced by cells in one area of the plant and then transported to a different area to produce a response

Question 3

Describe the main functions of auxins.

Answer 3

They stimulate growth by causing cell elongation and they also help to regulate fruit development. Without auxins, fruits are often too small.

Question 4

Describe the main functions of ethene.

Answer 4

They cause plant fruits to ripen by stimulating the conversion of starch into sugar. It is the only plant hormones that exists as a gas

Question 5

Describe the main functions of gibberellins.

Answer 5

They promote growth, particularly stem elongation. They can also end the dormancy period of seeds and buds, which leads to shoots and flowers opening.

Question 6

What are some commercial uses of plant hormones?

Answer 6

Speeding up or slowing down plant growth.

Question 7

What do many weed killers contain?

Answer 7

Auxins

Question 8

What are weed killers?

Answer 8

Selective herbicides which kill weeds that are broad-leaved plants but do not affect narrow-leaved plants.

Question 9

How does the auxin weedkiller kill weeds?

Answer 9

It makes the weeds grow too fast, and the rapid uncontrolled growth kills the plant

Question 10

What does rooting powder contain?

Answer 10

Auxins

Question 11

What do horticulturists and gardeners use auxin for?

Answer 11

Producing identical plants

Question 12

How are identical plants produced?

Answer 12

The plant shoot is cut off, dipped into rooting powder and planted.

Question 13

How is ripening delayed?

Answer 13

Auxin is sprayed onto fruit trees

Question 14

Why is ripening delayed/

Answer 14

So a harvest can be collected all at the same time and fruit won’t drop off trees early

Question 15

How is ripening quickened?

Answer 15

Ethene is sprayed onto fruit trees and plants

Question 16

Why is ripening quickened?

Answer 16

So fruit can be ready earlier in the growing season

Question 17

How can you produce seedless fruit?

Answer 17

Apply auxins to unpollinated flowers so insects and the wind cannot pollinate the plant and produce seeds

Question 18

Why is seedless fruit produced?

Answer 18

As some people like fruit without seeds

Question 19

Why do seeds not normally germinate at the end of summer?

Answer 19

As they remain dormant until conditions are ideal for growth

Question 20

How do commercial growers trigger seeds to germinate in the winter?

Answer 20

By spraying them with gibberellins or auxins in the greenhouse