Gene mutation

Question 1

What is mutation?

Answer 1

Any change to the base nucleotide sequence of DNA

Question 2

What are the three types of mutation?

Answer 2

• Substitution - one or more bases are swapped for another base
• Deletion - One or more bases are removed
• Insertion - One or more bases are added

Question 3

What is a frameshift mutation?

Answer 3

• Adding or deleting a base changes the number of bases present, causing a shift in all the base triplets that follow
• The rest of the DNA sequence is changes

Question 4

How does mutation not affect an organism?

Answer 4

• The amino acid that the triplet codes for doesn’t change (degenerate)
• The new amino acid is chemically similar to the original so it functons like the original amino acid
• The mutated triplet codes for an amino acid not involved with the protein’s function

Question 5

How does mutation have a positive effects on organism?

Answer 5

• Increase chances of survival
• E.g. Antibiotic resistance among bacteria

Question 6

How does mutation have a negative impact on organism?

Answer 6

• Decrease chance of survival e.g.
• Cystic fibrosis
• Breast cancer