An attribute of growth behavior of eight bacteriophage mutants (1 to 8) is investigated in experiments that establish coinfection by pairs of mutants. The experiments determine whether the mutants complement one another (+) or fail to complement (-). These eight mutants are known to result from point mutation. The results of the complementation tests are shown below.

Identify the mutants of each gene.

Verified step by step guidance

1. Step 1: Understand the concept of complementation testing. Complementation occurs when two mutations in different genes restore a functional phenotype when combined. If two mutants fail to complement (indicated by a '-' in the table), they are likely mutations in the same gene. If they complement (indicated by a '+'), they are likely mutations in different genes.
2. Step 2: Analyze the table systematically. Each mutant is tested against every other mutant. Look for patterns of '-' (failure to complement) to group mutants into the same gene. For example, if mutant 1 fails to complement mutants 3, 5, and 6, they may belong to the same gene.
3. Step 3: Group mutants based on the complementation results. Mutants that consistently fail to complement each other across the table are likely part of the same gene. For example, mutants 1, 3, 5, and 6 may form one group, while mutants 2, 4, 7, and 8 may form another group.
4. Step 4: Verify the grouping by cross-checking the table. Ensure that all mutants within a group fail to complement each other and complement mutants outside their group. This confirms the gene assignments.
5. Step 5: Assign mutants to specific genes based on the grouping. Label each group as Gene A, Gene B, etc., and list the mutants in each group. This provides the final identification of which mutants belong to each gene.

Key Concepts

Complementation

Complementation is a genetic phenomenon where two different mutations in a gene can restore the function of that gene when present together. In the context of bacteriophage mutants, if two mutants can complement each other, it indicates that they affect different genes or different parts of the same gene, allowing for normal function when combined.

Point Mutation

A point mutation is a change in a single nucleotide base pair in the DNA sequence. This type of mutation can lead to changes in the protein produced, potentially affecting its function. In the case of the bacteriophage mutants, each mutant results from a specific point mutation, which can help identify the genes involved based on complementation results.

Bacteriophage

Bacteriophages, or phages, are viruses that infect bacteria. They are often used in genetic studies due to their simple structure and ability to undergo rapid mutations. In this experiment, the growth behavior of different bacteriophage mutants is analyzed to understand the genetic basis of their functions and interactions during coinfection.