Biological Oxygen Demand (BOD) is a measure of: MCQ with Answer and Explanation

Explanation:
Hemoglobin is an iron-containing metalloprotein in erythrocytes that binds oxygen reversibly, forming oxyhemoglobin. Each molecule has four heme groups, each binding one O₂. Collagen is a structural protein, insulin a hormone, fibrinogen a clotting protein. Hemoglobin also carries some CO₂ and buffers blood pH.

Explanation:
Tetanus (lockjaw) is caused by the neurotoxin of Clostridium tetani, a soil bacterium that enters through wounds. The toxin causes muscle spasms and rigidity. Diphtheria is by Corynebacterium diphtheriae, pertussis by Bordetella pertussis, botulism by Clostridium botulinum (also a neurotoxin, but from food poisoning). Vaccination with DPT/tetanus toxoid prevents tetanus.

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.