Y13. Topic 8 - Grey Matter - Phytochrome and IAA - 07

What is the relationship between IAA concentration and cell elongation?

• Directly proportional

• Inversely proportional

• No relationship

• Random

What does the diagram suggest about the role of IAA in plant growth?

• It promotes growth

• It inhibits growth

• It has no effect

• It enhances photosynthesis

What does the diagram indicate about the concentration of IAA on different sides of the plant?

• Equal on both sides

• Higher on the side with amyloplasts

• Higher on the opposite side

• Random distribution

What is the result of genes being switched on?

• Genes are destroyed.

• Genes are not expressed.

• Production of polypeptides.

• Genes become inactive.

What happens to genes that are switched off?

• They are expressed.

• Polypeptides are produced.

• They are not expressed.

• They become active.

What can the length of night be detected by in a plant?

• The amount of sunlight.

• The quantities of different forms of a pigment.

• The temperature.

• The soil moisture.

What is the role of phytochrome in plants?

• Detecting soil nutrients

• Detecting the length of night

• Absorbing water

• Producing energy

What happens to polypeptides when genes are not expressed?

• They are produced.

• They are not produced.

• They are destroyed.

• They become active.

What is the primary function of phytochrome in the leaf?

• Absorbing sunlight

• Detecting night length

• Storing nutrients

• Producing chlorophyll

What part of the spectrum does the Pfr form of phytochrome absorb light from?

• Blue

• Far red

• Green

• Yellow