Types of mutation

Question 1

What are nonsense mutations?

Answer 1

• nonsense mutations result in a codon becoming a stop codon instead of coding for an amino acid
• this results in a shortned protein being synthesised
  
  • usually non-functional
• usually negative or harmful effects on phenotypes

Question 2

What are missense mutations?

Answer 2

• result in the incorportation of an incorrect amino acid (or amino acids)
• into the primary structure when the protein is synthesised
• the result depends on the role the amino acid plays in the structure and therefore the function of the protein synthesised
• couldbesilent, benefecial, or harmful

Question 3

What is a conservative mutations?

Answer 3

• occurs when the amino acid change leads to an amino acid being coded for whcih has similar properties to the original
• this means the effect of the mutations is less severe
• can also be a non-conservative mutation (different properties cba to make new flashcard more likely to cause disease x)

Question 4

What is an example of a recent mutation?

Answer 4

• ability to digest lactose,
• thought to be the result of a relatively recent mutation
• most mammals in the world become lactose intolerant after they cease to suckle
• found primarily in European populations
  
  • who are more likely to farm cattle
• helps prevent osteoprosis
• prevents starvation during famines

Question 5

What are the different changes in chromosome structure?

Answer 5

• deletions
  
  • a section of chromosome breaks off and is lost within the cell
• duplication
  
  • sections get duplicated on a chromosome
• translocation
  
  • a section of one chromosome breaks off and joins another non-homologous chromosome
• inversion
  
  • section of chromosome breaks off, is reversed, and then join back onto the chromosome