Plant responses 0.0 / 5 ? BiologyHuman, animal and plant behaviourA2/A-levelOCR Created by: laelle1479Created on: 09-01-17 11:45 What are biotic components? Components of the environment that are living 1 of 23 What are abiotic components? Components of the environment that are not living 2 of 23 Why is it important that plants and animals respond to the environment? So that they can survive long enough to reproduce 3 of 23 What are 3 chemical defences that plants employ when threatened by herbivores? Tannins, Alkaloids + Pheromones 4 of 23 What are tannins? Bitter tasting phenolic compounds found in the upper epidermis of leaves 5 of 23 What are alkaloids? Amino acid derived compound that have important physiological effects on animals; nicotine, morphine, quinine and strychnine 6 of 23 What are pheromones? Chemicals released by one living thing that effects the physiology and behaviour of another living thing 7 of 23 What are tropisms? Directional growth responses of plants towards (+) or away (-) from the stimulus 8 of 23 What are nastic repsonses? Non-directional responses to external stimuli 9 of 23 What is a phototropic response? A shoot grows towards the light (positive), enabling them to photosynthesise 10 of 23 What is a gravitropic response? Roots grow towards the pull of gravity anchoring them into the soil and allowing them to uptake water and mineral ions 11 of 23 What is chemotropism? Pollen tubes of a flower grow down the style, attracted by chemicals, towards the ovary where fertilisation occurs 12 of 23 What is thigmotropism? Shoots of climbing plants wind around another plant or solid structure for support 13 of 23 What do plant hormones do? Coordinate/control plant responses to environmental stimuli 14 of 23 Where are plant hormones produced in the plant? In a variety of tissues- they travel to target cells 15 of 23 How do hormones move around the plant? Active transport, diffusion, mass flow in the phloem sap or xylem vessel 16 of 23 What effects do cytokinins have on plants? They promote cell division and expansion, delay leaf ageing (senescence) and overcome apical dominance 17 of 23 What effects does abscisic acid have on plants? They inhibit cell germination and growth and cause the stomata to close when there's low water availablility 18 of 23 What effects do auxins have on plants? They promote cell elongation but inhibit lateral bud growth and leaf abscission (fall) 19 of 23 What effects do gibberellins have on plants? They promote seed germination and the growth of stems 20 of 23 What effects do ethene have on plants? Promote fruit rippening 21 of 23 What is apical dominance? Inhibition of lateral bud growth in the shoot due to chemicals produced by the apical bud 22 of 23 What is an auxin? A plant hormone that is responsible for regulating plant growth 23 of 23
Comments
No comments have yet been made