What change occurs by changing one base in DNA:
1.  Always a change of one amino acid in protein
2.  Change in complex sequence of amino acid
3.  Always a change in property of protein
4.  Does not necessarily change the phenotype

Minor change in a gene's structure is called:
1.  Reversible mutation
2.  Point mutation
3.  Forward mutation
4.  Backward mutation

Point mutation involves:

1. insertion

2. change in single base pair

3. duplication 

4. deletion

Change in the sequence of nucleotides in DNA is called:

1. Mutagen

2. Mutation

3. Recombination

4. Translation