Topic 10 - Plant Responses To Internal And Signals

Question 0

Acid growth hypothesis.

Answer 0

A model for the molecular mechanisms behind the induction of growth from Auxin.

• Auxin stimulates proton pumps
• Acidity in the apoplast increase (increase in hydrogen ions)
• Hemicellulose is loosened and cut by two enzymes
• Cells expand due to osmotic gradient induced by anion transfer across PM.

Question 1

What are the three primary functions of The plant hormone family called Auxins?

Answer 1

Stem elongation,phototropism, gravitropism.

Question 2

Phototropism

Answer 2

The plant response induced by light.

Question 3

What is the triple response?

Answer 3

A biological response that allows germinating plants to move around barriers.

Question 4

What are the three components of the triple response?

Answer 4

1) Shortening
2) Hook
3) Thickening

Question 5

Photo chrome

Answer 5

Receptors for light.

Question 6

Receptors

Answer 6

Proteins that undergo changes in shape in response to specific stimuli.

Question 7

Signal Transduction.

Answer 7

The amplification of the original signal by using secondary messengers.

Question 8

What is the function of the class of plant hormones called gibberellins?

Answer 8

1) Stem Elongation
2) Germination
3) Fruit Development

Question 9

Abscisic Acid.

Answer 9

Plant stress hormone that is consider the “anti-hormone” since it opposes other growth hormones.
Functions to:
Induces stomatal closure through proton pumps which create an chemi-osmotic gradient that causes water to rush out of the cell.

Question 10

Apical dominance.

Answer 10

The promotion of the primary growth over the growth of off-branches.

Question 11

Cytokinins

Answer 11

Class of plant hormones that function in:

1) cell division
2) cell differentiation