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21 Cards in this Set
- Front
- Back
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Why plants need to respond to the environment |
To avoid abiotic stress (non-living e.g drought) and predation |
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Definition of tropism |
Response of a plant to a directional stimulus |
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What is negative phototropism and give an example. |
Growth of a plant away from light e.g roots |
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What are hormones in plants called? |
Plant growth regulators |
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2 ways in which hormones move around the plant |
Active transport and diffusion |
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What happens to the distribution of auxins in a plant when exposed to a light source? |
Auxins gather to the shaded part of the shoots and roots. |
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What do auxins promote and inhibit? |
Promote cell elongation. Inhibit side shoots and abscission |
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What are gibberellins responsible for? |
Seed germination , stem elongation |
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What is meant by antagonistic and synergistic? |
Antagonistic : hormones opposing each others actions. Synergistic: hormones working together to cause big effect |
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The tip of the shoot is the apical bud. What happens when the apical bud is removed? |
Apical dominance wont occur as the apical bud wont produce auxins so side shoots begin to grow making a plant bushier. |
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What are deciduous plants? |
Plants that lose their leaves in the winter. |
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Differences between auxins and ethene in leaf loss (abscission). |
Auxins- produced by young leaves, as leaf gets older less auxin produced. Ethene- produced by ageing leaves, as leaf gets older more ethene produced. |
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How does ethene stimulate abscission? |
Abscission layer develops where the stem and lead join. Ethene stimulates cells in abscission layer to expand, breaking the cell walls and causing the leaf to fall off. |
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What are gibberellins responsible for? |
Seed germination , stem elongation |
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What is meant by antagonistic and synergistic? |
Antagonistic : hormones opposing each others actions. Synergistic: hormones working together to cause big effect |
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The tip of the shoot is the apical bud. What happens when the apical bud is removed? |
Apical dominance wont occur as the apical bud wont produce auxins so side shoots begin to grow making a plant bushier. |
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What are deciduous plants? |
Plants that lose their leaves in the winter. |
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Differences between auxins and ethene in leaf loss (abscission). |
Auxins- produced by young leaves, as leaf gets older less auxin produced. Ethene- produced by ageing leaves, as leaf gets older more ethene produced. |
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How does ethene stimulate abscission? |
Abscission layer develops where the stem and leaf join. Ethene stimulates cells in abscission layer to expand, breaking the cell walls and causing the leaf to fall off. |
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Name a commercial use of gibberellins? |
Sprayed on unpollinated flowers to develop fruits without fertilisation e.g seedless grapes |
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Commercial uses of auxins |
- developing seedless fruits - used in herbicides - taking cuttings |
