Which of the following statements could describe the result of a single mutation of a gene coding for a protease enzyme in a fertilised human egg cell?
1 A new allele is formed coding for a protease enzyme that works more efficiently.
2 A new allele is formed coding for a protease enzyme that works less efficiently.
3 A new allele is formed coding for a non-functional protein that has no effect on the cell.
4 A new allele is formed coding for a non-functional protein that has a negative effect on the cell.

Answer:

17) G

Statements 1 and 4 are termed gain of function mutation. This is a type of mutation in which the altered gene possesses a new molecular function. So these statement are correct. 

Statement 2 and 3 are termed loss of function mutation. These mutations result in the product having less or no function. So theses statement as are correct.