Random Fertilisation & Genetic Variation (Edexcel IGCSE Biology): Revision Note

Random Fertilisation & Genetic Variation

• Meiosis creates genetic variation between the gametes produced by an individual

• This means each gamete carries substantially different alleles

• During fertilisation, any male gamete can fuse with any female gamete to form a zygote

• This random fusion of gametes at fertilisation creates genetic variation between zygotes as each will have a unique combination of alleles

• Zygotes eventually grow and develop into adults

• Examples of genetic variation in humans include:

  • Blood group

  • Eye colour

  • Gender

  • Ability to roll tongue

  • Whether ear lobes are free or fixed

Whether earlobes are attached (lobeless) or free (lobed) is an example of genetic variation