variation

• What is meant by variation in biology?

  Variation refers to all the differences in the characteristics of individuals in a population.
• What are the three main causes of variation in a population?

  The three main causes of variation are genetic causes, environmental causes, and a combination of genes and the environment.
• What is an example of genetic variation in humans?

  Examples of genetic variation include hair color and eye color.
• How does the environment cause variation in characteristics?

  Environmental factors can influence characteristics, such as the color of flowers depending on the pH of the soil.
• What is an example of variation caused by a combination of genes and the environment?


  An example is human height, which is influenced by both genetics and diet.
• What is the role of mutations in genetic variation?

  Mutations are random changes to DNA that contribute to genetic variation.
• How do most mutations affect the phenotype?


  Most mutations have no effect at all on the phenotype.
• What is a key example of a mutation that can influence phenotype?


  An example is alleles for tallness that may lead to tallness if the diet is suitable.
• What is a rare outcome of mutations in terms of phenotype?

  Very rarely, mutations can lead to a new phenotype.
• How can a beneficial mutation affect a species?

  A beneficial mutation can lead to a rapid change in the species if the environment changes.
• What happened to the rabbit population in the UK in the 1950s?

  A mutation occurred that made surviving rabbits resistant to a virus, leading to a new beneficial phenotype.
• What is the significance of the mutation in the UK rabbit population?

  This mutation resulted in a new phenotype that became widespread in the UK rabbit population.
• What are the different types of variation and their causes?

  • Genetic Variation: Caused by alleles inherited (e.g., hair color, eye color).
  • Environmental Variation: Caused by environmental factors (e.g., flower color due to soil pH).
  • Combined Variation: Resulting from both genes and environment (e.g., human height).
• What is the relationship between mutations and genetic variation?

  • Mutations are random changes to DNA.
  • They contribute to genetic variation.
  • Most mutations have no effect on phenotype.
  • Rarely, mutations can lead to new phenotypes, which can be beneficial.
• What should you be able to describe by the end of the video on evolution?

  What's meant by evolution
• How does evolution take place according to the video?

  Through natural selection
• How many different species of animals and plants are estimated to exist on Earth?

  Nearly 9 million
• What percentage of species that have ever lived on Earth are thought to be extinct?

  99%
• How long ago is it believed that life first developed on Earth?

  More than 3 billion years ago
• What were the first life-forms on Earth described as?

  Very simple, for example, single cells
• What is the process called through which all species of living things have evolved from simple life forms?

  Evolution by natural selection
• What is a good example of genetic variation within a population mentioned in the video?

  Rabbits
• What do rabbits inherit from their parents that contributes to genetic variation?

  A combination of alleles
• If the environment gets colder, which rabbits are more likely to survive?

  Rabbits with alleles for thicker fur
• What happens to the alleles for thicker fur over many generations in a colder environment?

  They become more common among the population
• How does the introduction of a predator, like a fox, affect the rabbit population?

  Rabbits with alleles for better eyesight or hearing have an advantage
• What is the result of rabbits with better eyesight or hearing in the presence of a predator?

  They are more likely to survive and reproduce
• What is the definition of evolution as stated in the video?

  The change in the inherited characteristics of a population over time through natural selection
• What can happen when two populations of one species become so different in phenotype?

  They can no longer interbreed to produce fertile offspring
• What is an example of two different species mentioned in the video?

  Normal-sized rabbits and pygmy rabbits
• Why can't pygmy rabbits breed successfully with normal-sized rabbits?

  Because they are so small that they cannot interbreed
• What are the key points of natural selection as described in the video?

  • Genetic variation exists within a population
  • Environmental changes favor certain traits
  • Individuals with advantageous traits are more likely to survive and reproduce
  • Beneficial alleles are passed on to offspring
  • Over generations, these traits become more common in the population
• What resources are available for further questions on evolution by natural selection?

  • Vision world book
  • Link provided in the video
• What is another term for selective breeding?

  Artificial selection
• What should you be able to explain regarding the impact of selective breeding?

  The impact of selective breeding of food plants on domesticated animals
• What are the disadvantages of selective breeding?

  It can lead to inbreeding and associated health issues
• What animal is shown as an example of selective breeding in the material?

  Wolf
• Why did humans begin to selectively breed wolves?

  Because wolves can alert humans to threats and provide companionship
• What process was used to produce the dogs we see today from wolves?

  Selective breeding
• What are four examples of selective breeding mentioned in the material?

  • Domestic dogs bred for a gentle nature
  • Food crops like wheat bred for disease resistance
  • Cows bred to produce more meat or milk
  • Plants bred for large or unusual flowers