Genetic diagrams

• What do genetic diagrams show?

  Combinations of alleles from two parents
• What does the dominant allele 'A' code for in mice?

  Normal amounts of average muscle
• What does the recessive allele 'a' code for in mice?

  Muscular mass
• How are alleles represented in genetic diagrams?

  As uppercase and lowercase letters
• What does a homozygous normal mouse's genotype look like?

  Capital A, capital A
• What is the phenotype of a homozygous muscular mouse?

  Muscular
• How do you find the gametes from a parent's genotype?

  Split the letters into separate circles
• What do you do to find the offspring's genotypes?

  Combine the gametes from both parents
• What is the result when a capital A gamete combines with a lowercase a gamete?

  Capital A, lowercase a genotype
• What does heterozygous mean?

  One allele of each type
• What phenotype do all heterozygous offspring have?

  Normal phenotype
• What is a Punnett square used for?

  To show genetic combinations visually
• How does a Punnett square differ from a genetic diagram?

  Punnett squares are simpler to draw
• What is the outcome ratio of normal to muscular mice from two heterozygous parents?

  3 to 1 ratio
• What is the probability of having muscular offspring from two heterozygous parents?

  One in four or 25%
• What is the genotype of the offspring when two heterozygous mice mate?

  One homozygous dominant, two heterozygous, one homozygous recessive
• What is the phenotype distribution from two heterozygous mice?

  Three normal and one muscular
• What factors influence traits in organisms?

  • Multiple genes interact
  • Environmental factors play a role
• What is the importance of food and sleep in growth?

  They affect height and overall growth