genes and alleles

• What genes you inherit control the characteristics you develop
• Different genes control different characteristics
• Some characteristics are controlled by a single gene, but most are controlled by several genes interacting
• All genes exist in different versions called what?

  alleles
• How many alleles do you have of every gene in your body?

  2
• If an organism has two alleles for a particular gene that are the same, then they are..

  homozygous
• If an organism has two different alleles for a particular gene, then they are..

  heterozygous
• Dominant alleles are represented with a

  capital letter
• Recessive alleles are represented with a

  lower case letter
• If a dominant allele is present, which kind of characteristic will be shown?

  dominant
• If there is no dominant allele present, what kind of characteristic will be shown?

  recessive
• If there are two dominant alleles present, the characteristic will be..


  dominant
• Your genotype is the combination of

  alleles
• Your phenotype is your


  characteristics
• How many pairs of chromosomes is in a typical body cell

  23 pairs
• 22 pairs of your chromosomes are matched pairs but the 23rd pair determine sex
• XX is


  female
• XY is

  male
• What is the chance that sperm is male or female?

  50%
• Egg cells will always have which chromosome?

  x
• What is the square we use to show genetic probability?

  punnett square