Plant Growth and Response Mechanisms

The video explores plant adaptations, focusing on phototropism and gravitropism. It discusses experiments by Darwin and Boysen-Jensen, highlighting the role of auxin in plant growth. The video concludes with an explanation of how plants use gravitropism to grow against gravity.

What is the main focus of plant adaptations discussed in the introduction?

• How plants reproduce

• How plants seem to 'know' where light is

• How plants adapt to different climates

• How plants use photosynthesis

What is phototropism?

• The tendency of plants to grow towards a light source

• The method by which plants absorb water

• The way plants reproduce

• The process of photosynthesis

In Darwin's experiments, what happened when the top of the plant was removed?

• The plant died

• The plant grew faster

• The plant stopped bending towards the light

• The plant bent more towards the light

Which part of the plant is crucial for sensing light and initiating bending?

• The roots

• The leaves

• The top of the plant

• The stem

What did the Boysen-Jensen experiments demonstrate about plant bending?

• It requires a chemical signal

• It happens only in the roots

• It is due to sunlight exposure

• It is caused by water absorption

What is the role of auxin in plant growth?

• It helps plants absorb water

• It protects plants from pests

• It is a nutrient for plant roots

• It regulates plant growth and bending

How does auxin affect plant growth in relation to gravity?

• It makes plants grow faster

• It influences plants to grow against gravity

• It has no effect on plant growth

• It causes plants to grow sideways

What is gravitropism?

• The process of plants growing towards light

• The tendency of plants to grow in response to gravity

• The way plants absorb nutrients

• The method by which plants reproduce

What is positive gravitropism?

• Growth of plant roots towards gravity

• Growth of plant leaves away from light

• Growth of plant flowers towards the sun

• Growth of plant stems towards light

What is negative gravitropism?

• Growth of plant leaves towards light

• Growth of plant stems against gravity

• Growth of plant roots away from gravity

• Growth of plant flowers away from the sun