B6

• What is asexual reproduction?

  One parent cloning genetically identical offspring
• What is sexual reproduction?

  Joining of male and female gametes
• What is meiosis?

  Formation of gametes through cell division

  
• What does homozygous mean?

  Two of the same alleles
• What is a heterozygote?

  Two different alleles
• What is a phenotype?

  Physical appearance of an organism
• What is a genotype?

  Genes present in an organism
• What does dominant mean in genetics?

  Trait expressed even if one allele present
• What does recessive mean in genetics?

  Trait expressed only if both alleles present
• What is DNA?

  Polymer with two strands in double helix
• What are the gametes in animals?

  Egg and sperm
• What are the gametes in flowering plants?

  Pollen and ovule
• What is cystic fibrosis?

  Disorder of the cell membrane caused by recessive alleles
• What are the symptoms of cystic fibrosis?

  Overproduction of mucus, digestive enzymes dysfunction
• What is polydactyl?

  Extra digit caused by a dominant allele
• How many chromosomes are in gametes?

  23 chromosomes
• Why is the number of chromosomes in gametes important?

  Ensures 46 chromosomes after fertilization
• What is the process of meiosis?

  Cells divide twice to form gametes

  
• What is the importance of mitosis?

  Produces genetically identical cells for growth
• What are the probabilities of phenotypes in cystic fibrosis inheritance?

  • 25% have cystic fibrosis
  • 50% are healthy carriers
  • 25% are completely healthy
• What is the difference between a gene and an allele?

  Gene codes for a protein; allele is a variant
• What is embryo screening?

  Checking embryos for inherited disorders
• What are economic concerns about embryo screening?

  High costs of treating disorders
• What are social concerns about embryo screening?

  Implies genetic problems are undesirable
• What are ethical concerns about embryo screening?

  Choosing traits like sex or eye color
• What is the human genome?

  Entire genetic material of an organism
• Why is the human genome important?

  Linked to diseases and tracing migration
• What is the percentage chance of having a girl?

  50%
• What is the percentage chance of having a boy?

  50%
• What is the genotype of a human male?

  XY
• What is the genotype of a human female?

  XX
• What is variation?

  Differences in characteristics among individuals
• How is variation caused?

  By genes from parents and environmental factors
• What is a mutation?

  A change in the DNA sequence
• What is evolution?

  Change in inherited characteristics over time
• What is a fossil?

  Remains of organisms from millions of years ago
• How can fossils be formed?

  Minerals replace parts of decaying organisms
• Why is there limited evidence for early life forms?

  Soft-bodied organisms left no traces
• Why do we accept Darwin's theory of evolution?

  Evidence from fossils shows traits are inherited
• How are new species formed?

  Populations become so different they can't interbreed