16. immunity that can be acquired naturally, such as when we are exposed to a bacterial or viral infection (such as measles), or that can be acquired artificially, such as when we receive a vaccine, is known as

Adaptive immunity

Explanation:

The adaptive immunity is also known as acquired immunity. It is a sub system of the overall immunity.

It can defined as the immunity which is not present in the body when we are born. It develops in the body when it is exposed to the pathogens no matter it is natural or artificial.

The acquired immunity can develop in the body and makes the body susceptible to infections and develops prevention for the next time when the body will be exposed for the next time.

those characteristics are cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaptation through evolution. some things, such as a virus, demonstrate only a few of these characteristics and are, therefore, not alive