Plant Biology Quiz

What is the cause of positive phototropism?

• Increased concentration of auxin on the side of the stem closest to the light

• Degradation of auxin on the side of the stem closest to the light

• Increased concentration of auxin on the side of the stem furthest from the light

• Degradation of auxin on the side of the stem furthest from the light

Which role does positive feedback play in fruit ripening?

• The production of ethylene leads to fruit ripening, which stops the production of ethylene.

• The production of ethylene leads to fruit ripening, which causes more ethylene production.

• The production of RuBP leads to fruit ripening, which stops the production of RuBP.

• The production of RuBP leads to fruit ripening, which causes more RuBP production.

When a plant cell grows, the cell wall must expand. Explain the role of auxin in cell wall expansion.

How has this response been brought about?

• A higher concentration of auxins on the light side caused faster photosynthesis.

• A higher concentration of auxins on the shaded side caused faster meiosis.

• A higher concentration of auxins on the shaded side caused faster cell elongation.

• A higher concentration of chloroplasts on the light side allowed for more photosynthesis.

What are the direction of movement and the effect of auxin in the tip of a plant shoot when receiving light from one side?

How does auxin contribute to phototropism?

• It increases production of light-sensitive proteins.

• It increases growth of cells on the shaded side of the stem.

• It inhibits growth of axillary buds.

• It inhibits stem elongation.

How does auxin exert its effect on plant cells?

• Acts directly on the cell wall, causing expansion

• Binds to a receptor resulting in expression of genes

• Causes the vacuole to absorb water and expand the cell

• Causes the cell to undergo cell division

• A

• B

• C

• D