Questions and Answers
What is the direction of growth of plant shoots in response to gravity?
What is the role of auxin in root growth?
What is the purpose of a clinostat in investigating gravitropism and phototropism?
What is the effect of uniform light distribution on a plant using a clinostat?
Signup and view all the answers
Why are gravitropism and phototropism important for plants?
Signup and view all the answers
Where is auxin produced in plants?
Signup and view all the answers
What happens to cell growth in shoots in response to auxin?
Signup and view all the answers
What is the direction of growth of plant roots in response to gravity?
Signup and view all the answers
What is the primary response of plant roots to light?
Signup and view all the answers
Which of the following statements is true about auxin?
Signup and view all the answers
What is the result of unequal auxin distribution in response to light and gravity?
Signup and view all the answers
What is the purpose of using controlled light exposure in experiments?
Signup and view all the answers
What is the relationship between gravitropism and phototropism in plant growth?
Signup and view all the answers
What is the effect of auxin on cell growth in roots?
Signup and view all the answers
What is the characteristic of the lower cell layer in roots?
Signup and view all the answers
What is the result of auxin accumulation on the lower side of the root?
Signup and view all the answers
What is the role of auxin in gravitropism and phototropism?
Signup and view all the answers
What is the significance of gravitropism and phototropism in plant growth and development?
Signup and view all the answers
Study Notes
Gravitropism
- Gravitropism is a response in plants where parts of the plant grow towards or away from gravity.
- Plant shoots display negative gravitropism, growing away from gravity.
- Plant roots display positive gravitropism, growing towards gravity.
Phototropism
- Phototropism is a response in plants where parts of the plant grow towards or away from light.
- Plant shoots are positively phototropic, growing towards light.
- Plant roots are negatively phototropic, growing away from light.
Role of Auxin
- Auxin is a plant growth regulator substance that plays a crucial role in gravitropism and phototropism.
- Auxin is produced in the shoot tip and root tip.
- Auxin spreads through the plant from the shoot tip, promoting cell elongation.
- Auxin is unequally distributed in response to light and gravity.
Auxin and Cell Growth
- In shoots, auxin stimulates cell growth, promoting cell elongation.
- In roots, auxin inhibits cell growth, restricting cell elongation.
Investigation of Gravitropism and Phototropism
- Clinostat is used to cancel out the effect of unilateral stimuli, allowing for uniform growth responses.
- Experiments involving clinostat and controlled light exposure demonstrate the effects of gravitropism and phototropism.
Importance of Gravitropism and Phototropism
- Gravitropism and phototropism help plants compete for light and carbon dioxide.
- They also facilitate pollination and seed dispersal.
Differences in Root and Shoot Responses
- Roots grow towards gravity, while shoots grow away from gravity.
- Auxin promotes cell growth in shoots, but inhibits cell growth in roots.
- Roots have a shorter lower cell layer, while shoots have a longer lower cell layer.
Key Concepts
- Auxin accumulation on the lower side of the root promotes cell growth.
- Auxin stimulation of cell growth in stems promotes upward growth.
- Uniform light distribution on a plant using a clinostat prevents phototropism.
- Removing the tip of a plant and placing it on an agar block allows for the study of auxin diffusion and its effect on cell growth.
Gravitropism
- Plants respond to gravity through growth, with shoots growing away from gravity and roots growing towards it.
Phototropism
- Plants respond to light through growth, with shoots growing towards light and roots growing away from it.
Role of Auxin
- Auxin is a plant growth regulator produced in shoot and root tips, promoting cell elongation through unequal distribution in response to light and gravity.
- Auxin spreads from the shoot tip, promoting cell growth in shoots and inhibiting it in roots.
Auxin and Cell Growth
- Auxin stimulates cell growth and elongation in shoots, but inhibits it in roots.
Investigation of Gravitropism and Phototropism
- Clinostat is used to cancel unilateral stimuli, allowing for uniform growth responses and investigations into gravitropism and phototropism.
- Controlled light exposure experiments demonstrate the effects of phototropism.
Importance of Gravitropism and Phototropism
- Gravitropism and phototropism enable plants to compete for light and CO2, and facilitate pollination and seed dispersal.
Differences in Root and Shoot Responses
- Roots and shoots respond differently to gravity, with roots growing towards it and shoots growing away from it.
- Auxin promotes cell growth in shoots but inhibits it in roots.
- Roots have a shorter lower cell layer, while shoots have a longer one.
Key Concepts
- Auxin accumulation on the lower side of roots promotes cell growth.
- Auxin stimulation of cell growth in stems promotes upward growth.
- Uniform light distribution using a clinostat prevents phototropism.
- Removing the tip of a plant and placing it on an agar block allows for the study of auxin diffusion and its effect on cell growth.
Gravitropism
- Plants respond to gravity through growth, with shoots growing away from gravity and roots growing towards it.
Phototropism
- Plants respond to light through growth, with shoots growing towards light and roots growing away from it.
Role of Auxin
- Auxin is a plant growth regulator produced in shoot and root tips, promoting cell elongation through unequal distribution in response to light and gravity.
- Auxin spreads from the shoot tip, promoting cell growth in shoots and inhibiting it in roots.
Auxin and Cell Growth
- Auxin stimulates cell growth and elongation in shoots, but inhibits it in roots.
Investigation of Gravitropism and Phototropism
- Clinostat is used to cancel unilateral stimuli, allowing for uniform growth responses and investigations into gravitropism and phototropism.
- Controlled light exposure experiments demonstrate the effects of phototropism.
Importance of Gravitropism and Phototropism
- Gravitropism and phototropism enable plants to compete for light and CO2, and facilitate pollination and seed dispersal.
Differences in Root and Shoot Responses
- Roots and shoots respond differently to gravity, with roots growing towards it and shoots growing away from it.
- Auxin promotes cell growth in shoots but inhibits it in roots.
- Roots have a shorter lower cell layer, while shoots have a longer one.
Key Concepts
- Auxin accumulation on the lower side of roots promotes cell growth.
- Auxin stimulation of cell growth in stems promotes upward growth.
- Uniform light distribution using a clinostat prevents phototropism.
- Removing the tip of a plant and placing it on an agar block allows for the study of auxin diffusion and its effect on cell growth.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about plant growth responses to gravity and light, including gravitropism and phototropism. Understand how plant shoots and roots react to these stimuli.
