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IGCSEBiologyEdexcelBiology (Modular)Unit 2Revision Notes4. Reproduction & InheritanceInheritanceRandom Fertilisation & Genetic Variation

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

Exam code: 4XBI1

Lára Marie McIvor

Last updated

Edexcel Biology (Modular): Unit 2Edexcel Science (Double Award): BiologyEdexcel Biology

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

Earlobes, IGCSE & GCSE Biology revision notes

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

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Lára Marie McIvor

Author: Lára Marie McIvor

Expertise: Biology, Psychology & Sociology Subject Lead

Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. Lára has a particular interest in the area of infectious disease and epidemiology, and enjoys creating original educational materials that develop confidence and facilitate learning.