Assertion (A): The genetic code is universal. Reason (R): The same codon codes for the same amino acid in all organisms. MCQ with Answer and Explanation

Explanation:
Polymerase chain reaction (PCR) uses Taq polymerase, primers, and thermal cycling to make millions of copies of a specific DNA sequence. Southern blotting detects DNA, electrophoresis separates, sequencing reads bases.

Explanation:
Hemoglobin in red blood cells binds oxygen in the lungs and releases it in tissues. Each hemoglobin molecule can bind four O₂ molecules. It also carries some CO₂.

Explanation:
Alexander Fleming, a Scottish bacteriologist, discovered penicillin in 1928. He returned from a vacation to find that a Petri dish containing Staphylococcus bacteria had been accidentally contaminated by a mold. He noticed a clear zone around the mold where the bacteria had been killed. The mold was identified as Penicillium notatum, and the antibacterial substance was named penicillin.