Plant Hormones A2 Biology Quiz

What is the primary function of auxins in plants?

• Inhibiting cell growth

• Regulating photosynthesis

• Promoting cell elongation and growth

• Stimulating flower production

How do auxins promote cell elongation in plants?

• By inhibiting the plasticity of the cell wall

• By decreasing the water content in the cell wall

• By promoting the formation of lignin in the cell wall

• By increasing the plasticity of the cell wall

Explain the role of auxins in phototropism.

• Auxins inhibit cell elongation on the shaded side of the stem.

• Auxins promote cell elongation on the shaded side of the stem.

• Auxins have no effect on phototropism.

• Auxins promote cell elongation on the sunny side of the stem.

Describe the role of auxins in gravitropism.

• Inhibiting cell elongation on the lower side of the stem

• Causing cell division on the upper side of the stem

• Preventing the stem from responding to gravity

• Promoting cell elongation on the lower side of the stem

What is the function of gibberellins in seed germination?

• Cause seed germination by reducing enzyme production

• Promote seed germination by breaking dormancy and stimulating enzyme production

• Have no effect on seed germination

• Inhibit seed germination by inducing dormancy and reducing enzyme production

How do gibberellins promote stem elongation in plants?

• By stimulating cell division and elongation in the stem

• By increasing leaf growth instead of stem growth

• By inhibiting cell division in the stem

• By reducing water uptake in the stem

Explain the role of gibberellins in fruit development.

• Gibberellins have no role in fruit development

• Gibberellins stimulate cell division and elongation in fruit development, leading to larger fruit size.

• Gibberellins inhibit fruit development by preventing cell division and elongation

• Gibberellins cause fruit to shrink and decrease in size

What are the different types of plant tropisms?

• Phototropism, geotropism, and thigmotropism

• Positive tropism, negative tropism, and lateral tropism

• Heliotropism, aerotropism, and rheotropism

• Hydrotropism, thermotropism, and chemotropism

Describe the mechanism of phototropism in plants.

• Auxin moves to the sunny side of the plant and inhibits cell elongation, causing the plant to bend away from the light source.

• Auxin moves to the shaded side of the plant and promotes cell elongation, causing the plant to bend towards the light source.

• Gibberellins move to the shaded side of the plant and inhibit cell elongation, causing the plant to bend towards the light source.

• Cytokinins move to the roots of the plant and promote cell elongation, causing the plant to bend towards the light source.

Explain the role of gravitropism in plant growth.

• Gravitropism helps plants orient themselves for optimal growth and nutrient uptake.

• Gravitropism is only important for animal growth

• Gravitropism has no role in plant growth

• Gravitropism causes plants to shrink and wither