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Video tutorials

Supplemental Videos

Click here to watch video tutorials for exam board specific videos by A* students

The Hardy-Weinberg principle

Selection and change of allele frequency

Natural selection

Stabilising selection

Directional selection

Disruptive selection

Reasons for a high incidence of a (dominant) rare disease/allele in a population [EXAM]


Reproductive Isolation Mechanisms



Allopatric speciation (geographical isolation)

Sympatric speciation (reproductive isolation)