Variation

• What is meant by variation in biology?

  Differences in characteristics of individuals
• What are the three main causes of variation?

  Genetic, environmental, and combined causes
• What is the first cause of variation?

  Inherited alleles
• Give an example of genetic variation.

  Hair color and eye color
• What are some examples of genetic variations in hair color?

  Red hair, blond hair, dark hair
• How does the environment cause variation in flowers?

  Color depends on the pH of the soil
• What is an example of variation caused by the environment in humans?

  Language
• How does height in humans illustrate combined causes of variation?

  Height is influenced by genes and diet
• What is the role of mutations in genetic variation?

  They cause random changes to DNA
• What is the effect of most mutations on phenotype?

  Most have no effect at all
• How can some mutations influence phenotype?

  They can lead to traits like tallness
• What is a key idea about mutations and phenotypes?

  Very rarely can lead to a new phenotype
• How can a new phenotype be beneficial?

  If the environment changes
• What happened to the rabbit population in the 1950s in the UK?

  A mutation made them resistant to a virus
• What is the significance of the mutation in the rabbit population?

  It provided a new beneficial phenotype
• Where can you find questions on variation for revision?

  In the revision workbook