Plant Responses (OCR A-Level Biology A): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
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Practise the questions
10 questions from this quiz
How do plant hormones differ from animal hormones?
How do plant hormones differ from animal hormones?
Produced by unspecialised cells
What happens to auxin when light shines on one side of a shoot tip?
What happens to auxin when light shines on one side of a shoot tip?
Redistributes to far side away from light
What is the role of expansins in plant cell growth?
What is the role of expansins in plant cell growth?
Loosen bonds between cellulose fibres
How does high auxin concentration affect root cells differently from shoot cells?
How does high auxin concentration affect root cells differently from shoot cells?
Inhibits root growth but promotes shoot growth
What is apical dominance?
What is apical dominance?
Apex auxins inhibit lateral bud development
Which functions are performed by gibberellins?
Which functions are performed by gibberellins?
Seed germination and stem elongation
What does synergism mean in relation to auxins and gibberellins?
What does synergism mean in relation to auxins and gibberellins?
Combined effect exceeds sum of individual effects
Which hormones control leaf abscission in deciduous plants?
Which hormones control leaf abscission in deciduous plants?
Ethene stimulates, auxins inhibit abscission
What happens when ABA triggers stomatal closure in guard cells?
What happens when ABA triggers stomatal closure in guard cells?
K+, NO3-, Cl- leave cell, causing turgor loss
Why do synthetic auxins work as selective weed killers in cereal fields?
Why do synthetic auxins work as selective weed killers in cereal fields?
Grasses far less sensitive than broadleaved weeds