Variation & Evolution

• What is the concept of variation in biology?

  Nothing is identical; variation exists.
• What are the two main types of variation?

  Heritable and environmental variation.
• What causes heritable variation?

  Differences in genes passed from parents.
• What is environmental variation caused by?

  Differences in the environment experienced.
• Can some features result from both heritable and environmental variation?

  Yes, some features can combine both types.
• What is continuous variation?

  Variation with a continuous range of traits.
• What is discontinuous variation?

  Variation with distinct groups or categories.
• What is the significance of mapping the human genome?

  It helps understand genetic differences and diseases.
• How does sexual reproduction contribute to genetic variation?

  Offspring inherit different genes from parents.
• What is a zygote?

  A cell formed from the fusion of sperm and egg.
• Why are siblings similar but different?

  They inherit a mix of genes from parents.
• What causes mutations in genes?

  Random changes in the genetic material.
• What is asexual reproduction?

  Reproduction without fertilization, identical offspring.
• How do mutations affect offspring?

  They can be harmful or beneficial to traits.
• What is the term for offspring that are genetically identical to their parent?

  Clones
• What is the role of cancer genes in cells?

  Cancer genes can lead to uncontrolled cell growth.
• What is the outcome of mutations in gametes?

  They can be passed to the next generation.
• How do mutations contribute to evolution?

  They introduce genetic diversity in populations.
• What are the two types of genetic differences in organisms?

  Genetic differences and environmental differences
• How do environmental factors affect phenotypes?

  They create differences in phenotypes
• What is the difference between continuous and discontinuous characteristics?

  Continuous characteristics show a range; discontinuous fall into categories
• How does sexual reproduction contribute to genetic variation?

  It mixes genetic information from parents
• What is the result of meiosis?

  Genetically different gametes
• What happens during fertilization?

  Gametes fuse to form a zygote
• What is a mutation?

  A random change in DNA base sequence
• What can cause mutations?

  Exposure to chemicals and radiation
• How can a gene mutation affect an organism?

  It may change the organism's phenotype
• What is cystic fibrosis?

  A recessive condition affecting mucus production
• What is gene therapy?

  Methods to prevent effects of defective genes
• What are the two methods of gene therapy?

  Insertion of a functional allele into DNA
• What are some ethical issues surrounding gene therapy?

  Cost, religious beliefs, health implications
• What is natural selection?

  Gradual change in traits within a population
• Who proposed the theory of natural selection?

  Charles Darwin and Alfred Wallace
• What happens when a species becomes extinct?

  All members of that species have died
• What are some reasons for extinction?

  Inability to adapt, competition, environmental changes
• What is the process of modeling natural selection using camouflage?

  1. Use a piece of blue paper.
  2. Disperse small squares of white and blue paper.
  3. Have a volunteer collect squares for 30 minutes.
  4. Record the number of squares remaining.
  5. Analyze the visibility of colors.
• What is the significance of the Human Genome Project?

  It mapped the entire human genome
• How does the Human Genome Project benefit medicine?

  Identifies disease-causing alleles and treatments
• How can scientists predict individual responses to drugs?

  By understanding gene interactions with lifestyle
• natural selection - which organisms are better suited to the environment are likely to survive.