Variation and evolution

• What factors can variation be due to?

  Genetic and environmental
• What is the genetic factor?

  Difference in genotypes due to the presence of different alleles
• What happens due to genetic factors?

  Differences in phenotypes
• What is the environmental factor?

  Differences in phenotypes due to the environmental factors?
• What’s an example of an environmental factor?

  Diet and lifestyle
• Can variation be due to both genetic and environmental factors?

  Yes
• What is genetic variation due to?

  Sexual reproductions and spontaneous mutations
• Why does sexual reproduction cause variation?

  Meiosis creates genetically different gametes so information from both parents is mixed to form a unique individual
• What are spontaneous mutations?

  A random change in the base sequence in DNA
• What could spontaneous mutations be due to?

  Exposure to chemicals
• What can mutations cause?

  Minor and complete changes
• What are the two types of variation?

  Continuous and discontinuous
• What is continuous variation?

  A trait that doesn’t fall into a distinct category
• What is an example of continuous variation?

  Height
• What is discontinuous variation?

  A trait that does fall into a distinct category
• Whats an example of discontinuous variation?

  Blood type
• What is an inherited disease?

  A disease caused by genetic mutations passed down from parents to their offspring.
• Whats an example of an inherited disease?

  Cystic fibrosis
• What do the alleles FF say about their cystic fibrosis condition?

  They don’t have it/ healthy
• What do the alleles Ff indicate about their condition to cystic fibrosis?

  Healthy but a carrier
• What do the alleles ff refer about their cystic fibrosis condition?

  They have cystic fibrosis
• What can family trees of people with cystic fibrosis be used to investigate?

  Their genotypes
• What is gene therapy?

  It’s used to counteract the effects of a defective allele within DNA
• What are the two methods used in gene therapy?

  • Replacing the faulty allele with a healthy one
  • ’Turning off’ the defective allele
• What are the ethical issues with gene therapy?

  • Expensive
  • Religious objections
  • Possible side effects
• What are the possible side effects that come with gene therapy?

  An immune response
• What is the structure used for natural selection?

  VISITED
• What does the V stand for in VISITED?

  Variation due to mutation
• What does the first I stand for in VISITED?

  Inherited- mutated alleles passed on to offspring
• What does the S stand for in VISITED?

  Selective pressure allow those with the mutation to survive
• What does the ITED stand for in VISITED?

  Over time all of the species have the mutation and are resistant
• Who proposed the theory of natural selection?

  Charles Darwin and Alfred Russel Wallace
• What theory did Charles Darwin also propose?


  ‘survival of the fittest’
• What is evolution?

  The gradual change in inherited traits within a population over time
• Why does extinction happen?

  • Organisms haven’t adapted
  • Haven't adapted quickly enough
  • Have been outcompeted
• What are two examples of modern day evolution?

  Antibiotic resistance and Warfarin resistant rats
• What is antibiotic resistance?

  When bacteria becomes adapted and survives the antibiotics
• What can antibiotic resistance lead to?

  Overprescription and misuse of antibiotics
• What was the human genome project?

  When the entire human genome was mapped by millions of scientists all over the world
• What did the Human Genome project help with?

  • To understand how lifestyle factors affect genes
  • To identity disease causing genes more quickly
  • To be able to predict response to certain drugs