Assertion (A): Bacteria can be killed by antibiotics like penicillin. Reason (R): Penicillin inhibits the synthesis of bacterial cell wall. MCQ with Answer and Explanation

Explanation:
The brain is the central and most complex organ of the nervous system, processing sensory information, controlling motor functions, and regulating higher cognitive processes. The heart is a muscular organ that acts as the central pump of the circulatory system, propelling blood through the network of blood vessels to deliver oxygen and nutrients. The lungs are a pair of spongy, air-filled organs that are the primary components of the respiratory system, facilitating the vital exchange of oxygen and carbon dioxide. All statements are correct.

Explanation:
Louis Pasteur provided strong evidence that microorganisms cause disease and developed pasteurization to kill pathogens. Koch formalized criteria linking specific microbes to specific diseases. Fleming discovered penicillin, Lister introduced antiseptic surgery.

Explanation:
James Watson and Francis Crick, using Rosalind Franklin's X-ray data, proposed the double helical structure of DNA in 1953.