exam qs lqc 6a

Question 1

Explain why a gene mutation involving the replacement of one base with another has less effect than the loss of a base.

Answer 1

loss causes whole amino acid sequence to change, replacement only changes one codon, number of amino acids remain the same

Question 2

Mutations to DNA can affect the structure of proteins produced in the cell.
Removing one base from a DNA sequence will affect the primary structure of a protein.
Changing one base for another may not affect the primary structure of a protein.
Explain why these two types of mutation have different effects on protein structure.

Answer 2

deletion could affect every codon on the mRNA, deletion more likely to affect the position of stop codon, deletion results in a different sequence of amino acids, substitution may code for the same amino acid