Plant Tropisms and Responses

The video explores the concept of tropism in plants, which is a growth movement towards or away from a stimulus. It covers different types of tropism: phototropism (response to light), geotropism (response to gravity), thigmotropism (response to touch), and chemotropism (response to chemicals). Each type is explained with examples, highlighting positive and negative tropism. The video also clarifies that not all plant movements, such as the closing of mimosa leaves, qualify as tropism since they do not involve growth towards or away from a stimulus.

What is the term for the growth movement of plants towards or away from sunlight?

• Chemotropism

• Phototropism

• Thigmotropism

• Geotropism

In phototropism, how do the roots of a plant typically respond to sunlight?

• They grow towards the sunlight.

• They grow away from the sunlight.

• They do not respond to sunlight.

• They grow horizontally.

What is the stimulus involved in geotropism?

• Light

• Chemicals

• Touch

• Gravity

Which part of the plant shows positive geotropism?

• The shoot

• The leaves

• The roots

• The flowers

What type of tropism involves a plant's response to touch?

• Thigmotropism

• Chemotropism

• Phototropism

• Geotropism

How do roots typically respond to rocks in thigmotropism?

• They grow around the rocks.

• They grow away from the rocks.

• They grow towards the rocks.

• They stop growing.

What is the stimulus in chemotropism?

• Chemicals

• Gravity

• Touch

• Light

In chemotropism, how does a pollen tube respond to chemicals?

• It grows randomly.

• It stops growing.

• It grows away from the chemicals.

• It grows towards the chemicals.

Why is the movement of Mimosa leaves not considered tropism?

• It is a response to chemicals.

• It is not a growth movement.

• It is a response to light.

• It involves growth movement.

What is a key requirement for a movement to be classified as tropism?

• It must involve a growth movement.

• It must be a temporary movement.

• It must involve a response to sound.

• It must occur only in roots.