Podcast
Questions and Answers
What is the effect of auxin accumulation on the side of the root facing water during hydrotropism?
What is the effect of auxin accumulation on the side of the root facing water during hydrotropism?
- It promotes elongation on that side
- It has no effect on elongation
- It inhibits elongation on that side (correct)
- It initially inhibits elongation, but then promotes it
In the case of hydrotropism in roots, the accumulation of auxins occurs on which side of the root?
In the case of hydrotropism in roots, the accumulation of auxins occurs on which side of the root?
- The accumulation of auxins is not involved in hydrotropism
- Both sides equally
- The side facing away from water
- The side facing water (correct)
In which of the following cases does tropism occur in the same direction as the accumulation of auxins?
In which of the following cases does tropism occur in the same direction as the accumulation of auxins?
- Negative phototropism for the root in a vertical position
- Positive geotropism for the root in a horizontal position
- Positive hydrotropism for the root
- All of the above (correct)
Which of the following statements about tropisms and auxin accumulation is NOT true?
Which of the following statements about tropisms and auxin accumulation is NOT true?
If a root is placed in a horizontal position, which tropism would cause it to curve downwards?
If a root is placed in a horizontal position, which tropism would cause it to curve downwards?
If a stem is placed in a vertical position, which tropism would cause it to curve towards a light source?
If a stem is placed in a vertical position, which tropism would cause it to curve towards a light source?
In which of the following cases does tropism have no effect?
In which of the following cases does tropism have no effect?
If a root is placed in a vertical position and exposed to a light source, which tropism(s) would cause it to curve away from the light source?
If a root is placed in a vertical position and exposed to a light source, which tropism(s) would cause it to curve away from the light source?
Which of the following statements about auxin accumulation and tropisms is correct?
Which of the following statements about auxin accumulation and tropisms is correct?
Flashcards
Tropism
Tropism
Plant growth direction in response to external stimuli.
Phototropism
Phototropism
Plant response to light causing stem growth.
Positive Phototropism
Positive Phototropism
Stem growing towards light.
Negative Phototropism
Negative Phototropism
Signup and view all the flashcards
Geotropism
Geotropism
Signup and view all the flashcards
Positive Geotropism
Positive Geotropism
Signup and view all the flashcards
Negative Geotropism
Negative Geotropism
Signup and view all the flashcards
Hydrotropism
Hydrotropism
Signup and view all the flashcards
Positive Hydrotropism
Positive Hydrotropism
Signup and view all the flashcards
Study Notes
Tropism
- Tropism is the curvature of a plant's stem or root in response to external stimuli such as light, humidity, and gravity.
- There are three types of tropism: phototropism, geotropism, and hydrotropism.
Phototropism
- Phototropism is the response of plant parts to light, causing curvature towards or away from the light.
- Stem is positive phototropic, meaning it grows towards the light.
- Root is negative phototropic, meaning it grows away from the light.
- Experiment: placing a seedling on a cork disc in a light-proof box with a small hole to admit light, and observing the stem's curvature towards the light and the root's curvature away from the light.
- Auxins play a crucial role in phototropism, with higher concentration of auxins on the side of the stem away from light, leading to faster growth and curvature towards the light.
- Lower concentration of auxins on the side of the root near light, leading to slower growth and curvature away from light.
Geotropism
- Geotropism is the response of plant parts to gravity, causing movement towards or away from the stimulus.
- Stem is negative geotropic, meaning it grows away from gravity.
- Root is positive geotropic, meaning it grows towards gravity.
- Experiment: germinating seeds in a soil and observing the stem's growth upwards and the root's growth downwards.
- Auxins accumulate in the lower side of both the root and the stem when the plant grows in a horizontal position, leading to negative geotropism in the stem and positive geotropism in the root.
Hydrotropism
- Hydrotropism is the response of plant parts to humidity, causing movement towards or away from the stimulus.
- Root is positive hydrotropic, meaning it grows towards water.
- Experiment: germinating seeds in two glass troughs with different water distributions, and observing the root's curvature towards the water at the sides.
- Auxins accumulate in the side of the root facing water, inhibiting cell elongation and leading to curvature towards the water.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
