Null mutation is
Null mutation/loss of function mutation/amorphic mutations:- These mutations are the result of gene product having less or no function. It occurs when the allele has a complete loss of function. Phenotypes associated with such mutations are most often recessive.
Mutation occuring in Non Coding region
Mutation that does not change the amino acid or end product
Mutation that codes for a change in progeny without any chromosomal change
Mutation that leads to no functional gene product