Control in plants 0.0 / 5 ? BiologyNervous system, hormones and behaviourGCSEAQA Created by: HeatherCreated on: 25-05-14 12:17 What are plant responses called and what do they do? tropisms which ensure that any growth is towards sources of light and water, 1 of 14 What is a tropism where light is gthe stimuli? phototropism 2 of 14 What is a tropism where gravity is gthe stimuli? Geotropism 3 of 14 In a shoot, what happens if light is the stimuli? Positive phototropism-Grows towards the light 4 of 14 In a root, what happens if light is the stimuli? Negative phototropism- Grows away from the light 5 of 14 In a shoot, what happens if gravity is the stimuli? Negative geotropism-Grows against the force of gravity 6 of 14 In a roots, what happens if gravity is the stimuli? Positive geotropism-Grows in the direction of the force of gravity 7 of 14 What are auxins and where in the plant are they found? A family of hormones found in plants on the tips of shoots and roots, 8 of 14 In high concentrations of auxins, what do cells in shoots do? Grow more 9 of 14 In high concentrations of auxins, what do roots do? Grow less 10 of 14 What shade of the shoot contains more auxins and why? The shaded side as it causes the shaded side to grow longer to bend towards the light 11 of 14 What shade of the roots contain more auxins and why? The shaded side contains less auxins so this side grows less so it grows away from the light, 12 of 14 Tissue culture is a type of asexual reproduction. Describe reproduction. (3marks) -Doesnt involve fertilisation of the fusion of gametes, -No genetic material is mixed, -Involves one parent only, -Produces a clone with no variation, 13 of 14 What is one advantage of using tissue culture and not using cuttings to produce plants? -It produces more offspring from one plant, -Less damage to plant, 14 of 14
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