Podcast Beta
Questions and Answers
What is the primary growth response of a plant when exposed to light?
Which of the following describes positive gravitropism?
In which part of the plant would you primarily observe the effects of phototropism?
What role does auxin play in plant growth?
Signup and view all the answers
What triggers the physiological mechanism of gravitropism?
Signup and view all the answers
Which of the following is an example of negative phototropism?
Signup and view all the answers
During which developmental phase can tropisms be observed?
Signup and view all the answers
How do roots utilize negative gravitropism?
Signup and view all the answers
Study Notes
Tropisms
- Plant responses to environmental stimuli
- Phototropism: growth in response to light
- Positive: growth towards light; example: sunflowers facing the sun
- Negative: growth away from light; example: compass plant orienting leaves parallel to sun rays
- Gravitropism/Geotropism: growth in response to gravity
- Positive: growth towards gravity; example: roots growing down
- Negative: growth away from gravity; example: stems growing up
- Other tropisms: temperature, touch, pH, communication chemicals, water, electric fields
- Tropisms can be observed in specific regions or certain developmental phases:
- Regions: roots, shoots, flowers
- Developmental phases: germination
Phototropism
- Positive: growth towards light; maximizes chemical energy usage
- Negative: : growth away from light; allows roots to seek nutrients & water
- Bending of plants is caused by auxin accumulation
- Auxin: hormone responsible for elongation; accumulates in darker regions of plants
Stem Gravitropism
- Stems or roots move towards or away from gravity
- Roots grow down (positive gravitropism)
- Stems grow up (negative gravitropism)
- Physiological mechanism: statoliths and amyloplasts
- Statoliths: rocks in seeds used to determine gravity direction
- Amyloplasts: trigger biochemical signals for gravitropic growth
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore how plants respond to various environmental stimuli through tropisms like phototropism and gravitropism. Understand the mechanisms behind positive and negative responses, and learn about the roles of hormones such as auxin. This quiz will test your knowledge on plant growth and adaptations.
