Edexcel IGCSE Biology 復(fù)習(xí)筆記 2.7.1 Diffusion in Gas Exchange Diffusion in Gas Exchange Diffusion is the?movement of molecules?from a region of its?higher?concentration to a region of its?l...
Abiotic & Biotic Conditions Niche The place where a species lives within an ecosystem is its?habitat The role that a species plays within its habitat is known as its?niche, including: Th...
Edexcel IGCSE Biology 復(fù)習(xí)筆記 2.6.3 Practical: Investigating Respiration Practical: Investigating Respiration We can investigate the production of carbon dioxide and heat from respiration through ...
Practical Skill: Investigating the Effects of Random Sampling on Allele Frequencies Investigations to mimic the effects of?random sampling?on?allele frequencies?in a population can be devised using...
Edexcel IGCSE Biology 復(fù)習(xí)筆記 2.6.2 Types of Respiration Aerobic Respiration Aerobic respiration requires oxygen It is defined as the chemical reaction in cells that uses oxygen to break down nutr...
Allopatric & Sympatric Speciation Evolution?causes?speciation: the formation of?new species?from pre-existing species over time, as a result of?changes to gene pools?from generation to g...
Reproductive Separation Reproductive separation In order for evolution to occur the new species population must be?genetically?and?reproductively separated?from the pre-existing species popu...
Evolution The?allele frequencies?(within the gene pool) of a population can?change?over time due to processes such as natural selection When the?allele frequencies?of a population change?suf...
Types of Selection & Their Effects Environmental factors that affect the chance of survival of an organism are referred to as?selection pressures For example, there could be high levels ...
