A scientist is studying a gene (grn) carried by a bacteriophage that allows a host bacterium to produce a green metabolic product before lysis. The scientist has four bacteriophage mutants for this gene. Mutant 1 has a nonrevertible mutation in grn while Mutants 2, 3, and 4 each have a revertible mutation in grn. After plating pairs of mutants and subsequent coinfection of host cells, the scientist observed the following:
| I. | Mutants 1 and 2: no green product |
| II. | Mutants 1 and 3: very rare green product |
| III. | Mutants 1 and 4: rare green product |
Which of the following is NOT consistent with these observations?
◦ A partial deletion in Mutant 1 overlaps a base-pair substitution in Mutant 2.
◦ Mutant 2 has a base-pair substitution at a different site than Mutant 3.
◦ Mutant 3 has a base-pair substitution at a different site than Mutant 4.
◦ Mutant 1's deletion is closer to the base-pair substitution in Mutant 3 than it is to the base-pair substitution in Mutant 4.
◦ A green product should be observed if coinfection occurs with mutants 3 and 4.
Studying
gene family
Attachment of gene clusters to the nuclear matrix
The bacterium Escherichia coli
Predicted polypeptide sequences translated from potential ORFs in the human TUBA3C gene
The locations of disease-causing mutations in the cystic fibrosis gene