Understanding Plant Tropisms and Responses

What is the primary role of auxin in phototropism?

• To inhibit cell elongation on the illuminated side of the plant

• To promote cell elongation on the shaded side of the plant

• To increase the production of chlorophyll

• To decrease the plant's sensitivity to light

How does the presence of an opaque cap on the tip of an oat seedling affect its growth in response to light?

• It causes the seedling to grow faster

• It prevents the seedling from bending toward the light

• It enhances the seedling's phototropic response

• It has no effect on the seedling's growth

Why is it important to rotate houseplants periodically?

• To ensure even distribution of water

• To prevent the plant from growing too tall

• To promote even growth by exposing all sides to light

• To increase the plant's resistance to diseases

What is the main difference between positive and negative phototropism?

• Positive phototropism involves growth away from light, while negative phototropism involves growth toward light

• Positive phototropism involves growth toward light, while negative phototropism involves growth away from light

• Positive phototropism involves growth toward gravity, while negative phototropism involves growth away from gravity

• Positive phototropism involves growth away from gravity, while negative phototropism involves growth toward gravity

In the context of gravitropism, what happens when a seedling is placed horizontally?

• Auxins accumulate on the upper side of the root and stem

• Auxins accumulate on the lower side of the root and stem

• The seedling stops growing

• The seedling grows in a spiral pattern

What would likely occur if a seed is planted with the root end facing upward?

• The root will grow upward, and the stem will grow downward

• The root will grow downward, and the stem will grow upward

• The seed will not germinate

• The seed will grow horizontally

Why does the root tip in photograph A, with the end cut off, not express gravitropism?

• The root tip is unable to sense gravity

• The root tip is unable to produce auxins

• The root tip is unable to absorb water

• The root tip is unable to photosynthesize

What is the effect of auxin concentration on the lower side of a horizontally placed stem?

• It inhibits cell elongation, causing the stem to grow downward

• It stimulates cell elongation, causing the stem to grow upward

• It has no effect on cell elongation

• It causes the stem to grow in a circular pattern

How can you determine if a plant is exhibiting positive or negative gravitropism?

• By observing the direction of root growth

• By measuring the plant's height

• By checking the color of the leaves

• By analyzing the plant's flowering pattern

What is the primary stimulus for phototropism in plants?

• Gravity

• Light

• Touch

• Temperature