Why are enzymes described as being like a lock and key?

Providing immunity by injecting the body with a weakened form a pathogen is known as

This is a coral reef ecosystem. many biotic and abiotic factors affect the health of this ecosystem. which set correctly pairs a biotic factor and an abiotic factor?

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents