Question

Suppose scientists study mutant bacterial strains of Staphylococcus aureus to find the order of the genes for tetracycline resistance (gene T), streptomycin resistance (gene S), erythromycin resistance (gene E), and penicillin resistance (gene P). They extract DNA from bacterial strains with one or more of these mutations and transform wild‑type bacterial cells (S+, E+, T+, P+) with the DNA.

Given that the P mutation is first, indicate the order of these bacterial genes within the genome according to the transformation experiment results.
Transformant genotype / % of all cells
P S+ E+ T = 20%
P S+ E T+ = 10%
P S E+ T+ = 10%
P S+ E T = 2%
P S E+ T = 1%
P S E T+ = 1%

Answer 1

The order of the bacterial genes within the genome, based on the transformation experiment results, is P-S-E-T.

Step-by-step explanation:

The order of the bacterial genes within the genome can be determined based on the transformation experiment results. Given that the P mutation is first, we can analyze the different transformant genotypes and their frequencies to deduce the order of the genes.

From the provided data, the order of the genes is P-S-E-T. The most common genotype is P S+ E+ T, which accounts for 20% of all cells. The other genotypes have lower frequencies, indicating that the genes are likely arranged in the order P-S-E-T.

Therefore, the order of the bacterial genes within the genome, based on the transformation experiment results, is P-S-E-T.