Two ways in which Single Nucleotide Polymorphisms (SNPs) identified in the human genome can bring revolutionary changes in biological and medical sciences are:

1. Personalized Medicine: SNPs can serve as genetic markers for predisposition to certain diseases or responses to medications. Understanding an individual's SNP profile can enable personalized treatment plans tailored to their genetic makeup, potentially leading to more effective and targeted therapies.

2. Disease Risk Assessment: SNPs associated with specific diseases can be used for early detection, risk assessment, and preventive measures. By analyzing SNP patterns in populations, researchers can identify genetic factors contributing to diseases and develop strategies for disease prevention and intervention.

In E.coli growing in a culture medium where lactose is present as a source of sugar, the lac operon operates as follows: Lactose serves as an inducer, binding to the lac repressor protein and causing it to undergo a conformational change. This change prevents the repressor from binding to the operator region, allowing RNA polymerase to bind to the promoter and initiate transcription of the lac operon genes.

Peptide bond formation occurs in the peptidyl transferase center of the large ribosomal subunit during translation. The amino acid-tRNA in the A site of the ribosome forms a peptide bond with the growing polypeptide chain attached to the tRNA in the P site, resulting in the transfer of the polypeptide chain to the amino acid in the A site.