The process by which bacteria reproduce asexually is: MCQ with Answer and Explanation

Explanation:
The Widal test is a serological agglutination test used to diagnose enteric (typhoid) fever, caused by Salmonella enterica serotype Typhi. It detects the presence of specific antibodies (O and H antigens) in the patient's serum against the O (somatic) and H (flagellar) antigens of the Salmonella typhi bacteria. A significant rise in antibody titer indicates an active or recent infection. It is not used for TB (Mantoux test), malaria (blood smear), or dengue (NS1/IgM).

Explanation:
Alveoli are tiny, thin-walled air sacs surrounded by a network of pulmonary capillaries. Oxygen diffuses from alveolar air into blood, and CO₂ diffuses from blood into alveolar air. Bronchi and bronchioles are air passages, trachea is the windpipe. The large surface area of alveoli (about 70 m²) facilitates efficient gas exchange.

Explanation:
Vitamins A, D, E, and K are fat-soluble vitamins, meaning they are absorbed along with fats in the diet and can be stored in the body's fatty tissue and liver. Vitamin C and the B-complex vitamins are water-soluble, meaning they dissolve in water and are not stored in significant amounts. Vitamin D deficiency causes rickets in children and osteomalacia in adults; scurvy is caused by Vitamin C deficiency. Thus, statements 1 and 2 are correct.