Topic 6 Survival Response Flashcards
What is tropism?
What is phototropism?
What is Gravitropism?
Tropism is directional growth response in plant.
Phototropism is growth of shoots and roots in response to light.
Gravitropism is growth of shoots and roots response to gravity
What occurs In phototropism in shoots?
Light hits tip of plant causing IAA diffuse to shaded side of the root the increase concentration of IAA promotes cell growth and cell elongation.
Cell elongation of shaded side causes shoot to bend towards light source.
What occurs in phototropism in roots?
IAA diffuses towards shaded side of the root
This inhibits growth and cell elongation so root bends away from light.
Where in the plant causes a positive phototropism?
Where in the plant causes negative phototropism?
Positive phototropism is in the shoots.
Negative phototropism is in the roots.
What happens when gravity acts on plant shoots?
Gravity acts on shoots and IAA diffuse towards the bottom due to gravity.increase IAA concentration promotes cell growth and cell elongation causing shoot to bend and grow AGAINST gravity.
What happens when gravity acts on the roots?
IAA diffuses towards the bottom due to gravity
Increase IAA concentration inhibits cell growth and cell elongation so roots bend and grows TOWARDS gravity so root grow downwards.
Where does positive Gravitropism happen in plants?
Where does negative Gravitropism happen in plants?
Positive Gravitropism happens in the shoots and roots.
NO Negative Gravitropism
What happens when there an increase concentration of IAA in roots?
When there is an increase concentration of IAA in shoots it inhibits cell growth and cell elongation.
What is the definition of Taxes?
What is positive taxis?
What is negative taxis?
Taxes is directional response in movement due to stimuli.
Positive taxis is towards stimuli.
Negative taxis is away from stimuli.
What is kineses?
Non-directional response to movement due to stimuli.
What is reflexes?
What is the effect is causes because of reflexes?
Reflexes is an extremely rapid response that doesn’t require thought.
Reflexes create a protective effect.
What is the pathway of reflexes?
1.stimuli detected by receptors send signals to
2.Sensory neurones then to spinal cord
3.Then passed to relay neurone through synapse
5.Synapse to motor neurone then to effector.
