Question

You have isolated a new mutation in the T4 bacteriophage rII A gene and you map its location within the gene by recombination frequency. You find that this new mutation fails to give wild type recombinants with several different adjacent mutations located in the same gene. What type of mutation is this new one you just isolated

Answer 1

A lethal mutation, thereby the resulting phenotype is not observed .

Explanation:

Lethal mutations are the result of genomic changes that may be lethal in certain conditions. In genetic research, this type of mutation has shown to be very useful in analyzing gene function (i.e., genes whose protein products are key for the survival of the organism in question), and they are perfect gene markers. In bacteriophages, for example, temperature-sensitive mutants of phage T4 that can not grow at temperatures higher 42°C have been identified (Edgar & Lielausis 1964).

Citation:

R. S. Edgar, & I. Lielausis (1964). Temperature-sensitive mutants of bacteriophage T4D: their isolation and genetic characterization. Genetics, 49(4), 649.