Chapter 16: Plant responses

Question 1

What is abscisic acid? (ABA)

Answer 1

Plant hormone that inhibits seed germination and causes stomatal closure when the plant is stressed by low water availability.

Question 2

What is abscission?

Answer 2

The fall of leaves.

Question 3

What are alkaloids?

Answer 3

Bitter-tasting compounds found in plant leaves that may affect the metabolism of animals or insects eating them or poison them.

Question 4

What is antagonism?

Answer 4

Working against each other for example when different plant hormones have opposite affect such as one promoting growth and one inhibiting it, the balance between them will determine the response of the plant.

Question 5

What is apical dominance?

Answer 5

Inhibition of the lateral buds further down the shoot by chemicals, such as auxins, produced by the apical bud at the top of the shoot.

Question 6

What are auxins?

Answer 6

Plant hormones such as IAA, that promote cell elongation, prevents leaf abscission, maintain apical dominance by inhibiting growth of side shoots, produce tropic responses and stimulate the use of ethene in fruit ripening.

Question 7

What are cytokinins?

Answer 7

Plant hormones that promote cell division, delay leaf senescence, overcome apical dominance, and promote cell expansion.