Name the category of causative agents of kala azar typhoid dysentery cholera commaon cold

Kala Azar: Leishmania parasites transmitted by biting of female phlebotomine sandflies.

Typhoid: Salmonella enterica serotype Typhi bacteria is the leading cause of typhoid worldwide.

Dysentery: There are two forms of dysentery

Cholera: Vibrio cholerae bacterium is the main culprit of cholera which produces several toxins that leads to the diseased condition.

Common cold: Common cold is generally caused by coronaviruses or rhinoviruses. However, other viruses have also been investigated in several studies.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.