ocr f215 ecosystems exam questions yep 4.5 / 5 based on 2 ratings ? BiologyEcology, ecosystems and environmental biologyA2/A-level Created by: sophieCreated on: 12-06-12 18:50 Suggest environmental conditions that are requited Climate Food availability Enough space/nesting sites Ammount of predetation Less interspecific compeition Less disease Low environmental resistance 1 of 7 Explain what is meant by sucession Natural changes in a species composition Directional change Over a period of time Reaching a climax community One sere changes conditions for the next Started by a pioneer species Creation of niches A number of recognisable stages 2 of 7 Explain what is meant by biodiversity Different species With different alleles all living together in a habitat/ecosystem 3 of 7 Outline Ecological, economical and ethical reasons Ecological Prevents disruption of food chains Maintainance of ecosystem/habitat Independence of species Economic Importance of large gene pool Some species not yet discovered can be used for medicines Fishing/agricultural purposes Tuourism Ethical Reduction oin biodiversity due to human activity Moral responsibility to put things right Fix it for future generations 4 of 7 List why tropical rainforests were destroyed Wood cut for export/sold Agricultural reasons eg growing crops/farming Cleared for towns Building roads Space for housess 5 of 7 Describe the important features of a tropical rain High biodiversity Deforestation reduces biodiversity Decrease in gene pool Acts as a carbon sink Remove CO2 from atmosphere Release CO2 when burnt Less photosynthesis, less O2 produced Transpiration contributes to atmospheric water content Destroys water cycle Rainforests supply crops eg nuts, rubber, fruit Some drugs found only in rainforests Soils become nutrient deficient, cant sustain agriculture without trees Increased risk of soil erosion Moral responsibility 6 of 7 Explain why biologyical pest control is preferred Insecticides harmful to other organimsms/ may kill natural predator to pest Reduces species diversity Many insecticides long lasting Bio-accumulate along food chain Damage to top carnivores, accumulation of herbicide eg shell thinning Poisonous to people applying them Pests can build up resistanc (natural selection) Run off contaminates water supplies Residues in food Pesticides must be repeated 7 of 7
OCR F215 Control, Genomes and the Environment revision PPT. 5.0 / 5 based on 1 rating Teacher recommended
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