The scientist who discovered the antibiotic streptomycin from soil bacteria was: MCQ with Answer and Explanation

Explanation:
Plasmids are small, circular, extrachromosomal DNA molecules in bacteria widely used as cloning vectors in genetic engineering. Restriction enzymes are part of the bacterial immune system, found in bacteria and archaea, not viruses, protecting them against bacteriophages. Polymerase Chain Reaction (PCR) requires a thermostable DNA polymerase (like Taq) to synthesize new DNA strands. Thus, statements 1 and 3 are correct.

Explanation:
The infundibulum connects them, and hypothalamic releasing/inhibiting hormones travel to the anterior pituitary; posterior pituitary stores hypothalamic hormones. R correctly explains A.

Explanation:
Carbon dioxide (CO₂) is the primary greenhouse gas, along with methane (CH₄), nitrous oxide (N₂O), water vapor, and CFCs. These trap heat in the atmosphere, leading to global warming and climate change. CO₂ levels have risen due to fossil fuel burning and deforestation. The greenhouse effect is natural and essential, but enhanced levels cause global temperature rise.