Genetics

• What is a pedigree diagram?

  A family tree showing inheritance patterns
• What is genetics the study of?

  Genes, heredity, and variation
• What is genetics the study of?

  Genes, heredity, and variation
• What does variation refer to in a population?

  Differences between individuals
• What are the two types of variation?

  • Genetic Variation: Caused by mutations, recombination, or gene flow.
  • Environmental Variation: Caused by external factors like diet, climate, or lifestyle.
• What is a mutation?

  A permanent change in DNA sequence
• What are the types of mutations?

  • Point Mutations: Changes in a single nucleotide.
  • Silent: No effect
  • Missense: Changes amino acid
  • Nonsense: Creates stop codon
  • Chromosomal Mutations: Large-scale changes.
  • Deletion, duplication, inversion, translocation
• What are the causes of mutations?

  Spontaneous errors and induced by mutagens
• How do environmental factors modify traits?

  • Traits like height and weight can be influenced.
  • Epigenetics: Modifications like DNA methylation affect gene expression without altering DNA.
• Who established the principles of Mendelian inheritance?

  Gregor Mendel
• What are Mendel's Laws of inheritance?

  1. Law of Segregation: Alleles separate during gamete formation.
  2. Law of Independent Assortment: Genes for different traits are inherited independently.
  3. Law of Dominance: Dominant alleles mask recessive alleles.
• What is the difference between genotype and phenotype?

  Genotype is genetic makeup; phenotype is physical expression
• What are homozygous and heterozygous genotypes?

  • Homozygous: AA or aa
  • Heterozygous: Aa
• How do Punnett Squares predict offspring ratios?

  • Used to visualize genetic crosses.
  • Example:
  • A A
  • A AA
  • a Aa
  • 100% offspring have dominant phenotype.
• What is multiple allelism?

  • Traits controlled by more than two alleles.
  • Example: ABO Blood Group System (A, B, O alleles).
• What are the genotypes for blood types in the ABO system?

  AA, AO → Blood Type A; BB, BO → Blood Type B; AB → Blood Type AB; OO → Blood Type O
• What is recombination in genetics?

  • Occurs during meiosis (Prophase I).
  • Crossing over exchanges genetic material between homologous chromosomes.
  • Increases genetic variation.
• What is sex linkage in genetics?

  • Genes located on sex chromosomes (X or Y).
  • X-linked traits are more common in males.
  • Example: Color blindness, hemophilia.
• What are the female and male genotypes for X-linked traits?

  • Female Genotype: XᴺXᴺ (Normal), XᴺXⁿ (Carrier), XⁿXⁿ (Affected)
  • Male Genotype: XᴺY (Normal), XⁿY (Affected)
• What does the Hardy-Weinberg principle predict?

  • Predicts allele frequencies in a population under ideal conditions.
  • Equations:
  • $p^2 +$$2pq +$$q^2 =$$1$ (Genotypic frequencies)
  • $p +$$q =$$1$ (Allelic frequencies)
• What do the variables p and q represent in the Hardy-Weinberg equation?

  p = frequency of dominant allele; q = frequency of recessive allele
• What are the assumptions of Hardy-Weinberg equilibrium?

  • Large population size (no genetic drift).
  • No mutations.
  • No natural selection.
  • Random mating.
  • No migration (gene flow).
• What are the mechanisms of evolution?

  1. Natural Selection
  2. Genetic Drift
  3. Gene Flow (Migration)
  4. Mutation
  5. Non-Random Mating
• What is natural selection?

  • Advantageous traits increase survival and reproduction.
  • Types: Stabilizing, Directional, Disruptive Selection.
• What is genetic drift?

  • Random changes in allele frequency due to chance events.
  • Stronger in small populations.
  • Examples: Bottleneck Effect, Founder Effect.
• What is gene flow?

  • Movement of alleles between populations.
  • Increases genetic diversity.
• What role do mutations play in evolution?

  • Introduce new alleles into a population.
  • Only source of brand-new genetic variation.
• What is non-random mating?

  • Preference for specific mates.
  • Can lead to sexual dimorphism.
• What are the final takeaways regarding evolution?

  • Genetic variation is essential for evolution.
  • Mutations, recombination, and independent assortment generate variation.
  • Mendelian genetics explains inheritance.
  • Evolution occurs through various mechanisms.