Plant Physiology and Experiments Quiz

What did Darwin demonstrate about the stimulus of unidirectional light in plants?

• It is detected by the base of the plant.

• It is detected by the tip of the coleoptile.

• It is detected by the roots.

• It is detected by the leaves.

What was the purpose of the experiments conducted between 1910 and 1926 on coleoptiles?

• To find a chemical messenger responsible for phototropism.

• To study the growth rate of plants.

• To analyze the color change in plants.

• To measure the water absorption in plants.

In Experiment 1, what material was used to demonstrate the passage of the growth stimulus?

• Plastic

• Metal

• Gelatin

• Wood

What was shown in Experiment 2 regarding phototropic response?

• It could be brought about without light by removing the coleoptile tip.

• It required direct sunlight.

• It was independent of any chemical.

• It was only possible in water.

What is the role of the hormone auxin in plant growth?

• It inhibits growth.

• It stimulates growth towards light.

• It causes leaves to fall.

• It changes the color of flowers.

What is a clinostat used for in plant physiology experiments?

• To measure water absorption.

• To demonstrate tropisms.

• To calculate plant height.

• To analyze soil composition.

What happens to the radicles of seeds on a clinostat when the motor is turned on?

• They grow upwards.

• They grow straight out horizontally.

• They stop growing.

• They grow in random directions.

What is the effect of auxin on the 'dark' side of a shoot?

• It inhibits growth.

• It stimulates growth, causing the shoot to bend towards the light.

• It causes the shoot to wilt.

• It has no effect.

What is the main function of plant hormones according to the text?

• To change the color of flowers.

• To influence growth and development.

• To absorb water.

• To produce seeds.

What is the significance of the 'cork side' in the experiments?

• It absorbs light.

• It stimulates growth.

• It blocks the hormone from diffusing.

• It changes the color of the plant.