Variation AS Unit 2

Variation AS Unit 2

1. Variation exists between all individuals:

   • INTERSPECIFIC: Variation that exists between different species e.g Horses vary from Ducks
   • INTRASPECIFIC: Differences that occur within a species e.g lenths of giraffes necks

2. INTRASPECIFIC is caused by genetic and enviromental factors

   • Genetic
     • Same Genes = Same species
     • Different versions of those genes are called alleles
     • The alleles an organism that has make up its GENOTYPE
     • Different genotype = variation in phenotype (characteristcs
     • You inherit from parents specific factors e.g eye colour
   • Enviromental
     • Phenotype affected by enviroment.
     • Fur colour
     • Plant Growth

3. Investigating Variation

   • Usally you take a sample of a population not whole thing because it is impossible and time consuming
   • Random Sample
     • Diving field in to a grid and use random generator
   • Standard Deviation
     • Tells you how much of the values in a single sample vary.
     • Large SD = Vary alot!
     • Small SD: Vary alittle around mean value

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