UNIT 4 BIOLOGY DEFINITIONS 3.5 / 5 based on 2 ratings ? BiologyEcology, ecosystems and environmental biologyA2/A-levelAQA Created by: TeganCreated on: 12-04-14 12:14 What is meant by a pest? An Organism that competes with humans for food and space. It could be a danger to health. It reduces the yield. 1 of 15 What is 'primary production'? The rate at which biomass is produced per unit area per unit of time by producers. 2 of 15 What is meant by biomass? Mass of organisms per unit area J/m2 3 of 15 What is meant by the standing crop? Bodies of living organisms within unit area, eg standing crop of primary producers at one time. 4 of 15 What is the gross primary product? the total amount of energy fixed by photosynthesis and is measured as Jm2 day or as dry mass kg/ha/yr 5 of 15 What is an agricultural ecosystem? It is made of domesticated animals and plants used to produce food for mankind. 6 of 15 What is productivity? The gross productivity - energy lost in respiration. 7 of 15 What is meant by the term ecosystem? The interaction between all of the biotic and abiotic features in one area at the same time. 8 of 15 What is Ammonification? Producing ammonia from organic ammonium containing compounds. This is carried out by saprobiotic microorganisms 9 of 15 What is nitrogen fixation? The process of turning nitrogen gas in to nitrogen containing compounds. 10 of 15 What is denitification? The process of turning nitrates back in to nitrogen gas 11 of 15 What is nitrification? Turning ammonium ions in to nitrites and then nitrates 12 of 15 What is meant by succession? the term used to describe the changes in the species colonising a particular area over a long period of time. 13 of 15 What is primary succession? when the community develops of bare, uncolonised ground which has never had any vegetation growing on it. eg lava and mud flows. 14 of 15 What is a community? A group of interacting populations 15 of 15
Comments
No comments have yet been made