Mendel's experiments were performed on which plant? MCQ with Answer and Explanation

Explanation:
Composite fish culture is a highly productive system used in inland fisheries (ponds) in India. It involves stocking a single pond with a combination of 5-6 different indigenous and exotic fish species that have complementary feeding habits (e.g., Catla are surface feeders, Rohu are column feeders, Mrigal and Common Carp are bottom feeders). This ensures that all available food resources in the different zones of the pond are utilized efficiently without interspecific competition, maximizing total yield.

Explanation:
Jonas Salk developed the first successful inactivated polio vaccine (IPV) in 1955. Albert Sabin later developed the oral attenuated vaccine (OPV). Jenner developed smallpox vaccine, Pasteur rabies, Koch identified tuberculosis bacillus. Polio has been nearly eradicated due to vaccination.

Explanation:
The 'lub' sound occurs at the beginning of ventricular systole when the atrioventricular valves (mitral and tricuspid) close to prevent backflow of blood into the atria. The 'dub' sound occurs at the beginning of diastole due to closure of the semilunar valves (aortic and pulmonary). Valve closure is passive, resulting from pressure gradients.