Genetics

• What is a change to a base called?

  A mutation
• How can some mutations affect the function of a protein?

  They can change the shape of the active site, preventing attachment to the substrate
• What might happen if a mutation changes the shape of a structural protein like collagen?

  It may lose its strength
• Do all parts of DNA code for proteins?

  No, some parts of DNA are non-coding
• What is the role of non-coding parts of DNA?

  They can switch genes on and off
• How can variations in non-coding areas of DNA affect gene expression?

  They may influence how genes are expressed
• What is the definition of genotypes?

  A genetic makeup of an organism
• What are phenotypes?

  The characteristic that is shown or expressed
• What does heterozygous mean?

  A person who has two different alleles for an inherited characteristic
• What does homozygous mean?

  A person who has two alleles that are the same for an inherited feature
• What are alleles?

  • Different forms of a gene
• What is polydactyly?

  Polydactyly is an inherited disorder where a person has extra fingers or toes.
• How is polydactyly inherited?

  Polydactyly is caused by a dominant allele.
• What type of substance does a gene code for?

  Protein
• Mutations sometimes mean there is less oxygen for respiration
• A dominant allele controls the development of a characteristic even when it is present on only one chromosome in a pair
• An allele which controls the development of characteristics only if a dominant allele is absent is called a recessive allele