The Cell Theory was proposed by: MCQ with Answer and Explanation

Explanation:
Gastrin is a hormone secreted by G cells in the stomach antrum, stimulating parietal cells to secrete HCl and promoting gastric motility. It is released in response to food in the stomach.

Explanation:
The anther is the male reproductive part of the flower where microspores develop into pollen grains. After fertilization, the ovary wall matures and develops into the fruit, enclosing the seeds. Self-pollination involves the transfer of pollen to the stigma of the same flower or plant, resulting in offspring genetically identical to the parent, thus decreasing, not increasing, genetic diversity. Thus, statements 1 and 2 are correct.

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).