Ecosystems Edexcel GCSE biology Newest Latest Study Guide Questions Fully Solved.

Producer - correct answer A plant that photosynthesises to produce food Consumer - correct answer An animal that eats plants or other animals Decomposer - correct answer Bacteria or fungi that decay dead material to recycle nutrients Population - correct answer All the organisms of a particular species found in an ecosystem at any one time Community - correct answer The populations of all the species found in an ecosystem at any one time Habitat - correct answer The place where a specific organism lives within an ecosystem e.g. pond water for a tadpole Ecosystem - correct answer A distinct self-supporting system of organisms interacting with each other and a physical environment, such as a mangrove swamp Examples of producers - correct answer Greens plants, phytoplankton and brown seaweed Trophic levels - correct answer The feeding levels in a food chain E.g. producers, consumers etc. Amount of energy transferred to each trophic level - correct answer 10% How energy is lost in a food chain - correct answer Faeces, dead animals, undigested biomass, heat, respiration and movement Pyramid of numbers - correct answer Shows the relative number of organisms at each stage of a food chain Pyramid of biomass - correct answer Shows the total mass of organisms at each stage of a food chain Assimilation Efficiency - correct answer The percentage of the total food eaten that is absorbed into the blood after digestion and not lost in faeces Production Efficiency - correct answer The percentage of assimilated food that is turned into biomass instead of being metabolised. Carbon Cycle - correct answer Water cycle - correct answer Nitrogen cycle - correct answer Denitrifying bacteria - correct answer Converts nitrates (use as food) to nitrogen gas Nitrifying bacteria - correct answer Converts ammonia into nitrates Free-living nitrogen fixing bacteria - correct answer Convert nitrogen gas into ammonia Nitrogen-fixing bacteria in root nodules - correct answer Make ammonia, too, but this is used by the plant for amino acids. Animals may also then eat the plants. Death and decomposition of the organisms return this to the soil as ammonia Lightning - correct answer Converts nitrogen gas into nitrates, which dissolve in rail water and enter into soil Decomposers (putrefaction) - correct answer produce ammonia from the nitrogen in compounds like proteins, DNA