Population Dynamics

Grazing food chain:} Starts with living plants (producers) that are consumed by herbivores (primary consumers). Example: Grass Grasshopper Frog Snake. Detritus food chain:} Begins with dead organic matter (detritus) that is consumed by decomposers (detritivores) like fungi and bacteria. Example: Dead leaves Earthworm Bird.

A vaccine is a biological preparation that provides active acquired immunity to a particular disease. Contains inactivated or weakened pathogens/antigens. Stimulates the immune system to produce memory cells for future protection.