Genetic diagrams

• What do genetic diagrams help predict?

  Characteristics passed from parents to offspring
• What are the two types of gene control over characteristics?

  • Single gene control
  • Several genes control
• What are alleles?

  Different versions of the same gene
• How do chromosomes come in pairs?

  There are two copies of each chromosome
• How many alleles do you have for every gene?

  Two alleles for every gene
• What does it mean if an organism is homozygous?

  Both alleles are the same
• What does it mean if an organism is heterozygous?

  Both alleles are different
• How are dominant alleles represented in genetic diagrams?

  With a capital letter
• How are recessive alleles represented in genetic diagrams?

  With a small letter
• What must be true for an organism to show a recessive characteristic?

  Both alleles must be recessive
• What is required for an organism to show a dominant characteristic?

  Only one allele needs to be dominant
• What is an organism's genotype?

  The genes and alleles it has
• What is an organism's phenotype?

  The characteristic that it displays
• What is single gene inheritance?

  • The way a single gene is passed from parents to offspring
  • Can be shown using genetic diagrams
• How do genetic diagrams help predict offspring phenotypes?

  By using the genotype of the parents
• What is the recessive allele for hamsters with superpowers?

  'b'
• What is the dominant allele for normal hamsters?

  'B'
• What happens when two homozygous hamsters (BB and bb) are crossed?

  • Offspring genotypes: Bb, Bb, Bb, Bb
  • Offspring phenotypes: All normal (boring)
• What is the genotype of a person with albinism?

  aa
• What should you remember about genetic diagrams?

  • They can be confusing at first
  • Understanding improves with practice
• How can the outcomes of a genetic cross be expressed?

  As probabilities or ratios
• What is the chance of offspring having superpowers in the genetic cross?

  25%
• What does a 1 normal : 1 superpower ratio indicate?

  Equal likelihood of each outcome
• How many pairs of chromosomes are in every human body cell?

  23 pairs
• What chromosomes determine male or female in humans?

  XX for female, XY for male
• What chromosome combination do males have?

  XY
• What chromosome combination do females have?

  XX
• What determines the sex of a baby?

  The sperm's chromosome (X or Y)
• What do all female gametes carry?

  An X chromosome
• What is the chance of having a male or female child?

  Equal chance
• What is classification in biology?

  • Organization of living things
  • Historical grouping methods varied
  • Evolved to complex systems
  • Based on evolutionary relationships
• How do scientists determine the relatedness of organisms?

  By examining their characteristics
• What is the hierarchy of natural classification?

  • Kingdoms
  • Phyla
  • Classes
  • Orders
  • Families
  • Genera
  • Species (most basic unit)
• How has the classification of living things changed over time?

  It has become more complex
• What is a significant difference between bacteria and plants or animals?

  Bacteria are fundamentally different organisms
• What role does DNA sequencing play in classification?

  Reveals relationships between species
• How does more information about species affect classification?

  It makes the classification more precise
• What is the current understanding of evolutionary relationships in classification?

  • Based on detailed characteristics
  • Subject to change with new information
• What do genetic diagrams indicate about outcomes?

  They show probabilities, not certainties
• What is the allele for wrinkly peas?

  Recessive allele r