IB ESS || with 100% Correct Answers.

environmental pressures correct answers the factors (abiotic or biotic) in an ecosystem which put pressure on an organism's survival and increase competition (whether inter-species or intra-species) biodiversity correct answers a combination of the species diversity, genetic diversity and habitat diversity of an ecosystem variation correct answers the differences, either physical or genetic, between individuals of a species simpson's diversity index correct answers a measure of diversity between similar ecosystems species diversity correct answers the number of species (richness) and their relative proportions (evenness) in a community genetic diversity correct answers the range of genetic material present in a gene pool or population of a species random genetic mutations correct answers the small differences which may occur in an organism as a result of reproduction - these small changes may add up to create variation hotspots correct answers an area of high biodiversity (which is under threat from human activities) endemic species correct answers the species which only occur in one specific area speciation correct answers the gradual change in populations of a species over time - often caused by geographical isolations, resulting in new species evolution correct answers the process by which a species may adapt to environmental pressures through natural selection of favourable variation - caused by random genetic mutations - over thousands of generations natural selection correct answers survival of the fittest - only the best suited organisms will be able to compete (due to environmental pressures) and so survive long enough to reproduce - their favourable traits are then passed on to new generations geographical isolation correct answers the separation of populations of a single species - often leads to speciation if populations cannot interbreed for a very long time physical barriers correct answers e.g. a mountain, ocean or separation of lakes land bridges correct answers a connection between land masses - often as a result of lowering sea levels e.g. the Bering Straits