Death is a natural and necessary part of life cycles, even at the cellular level. explain what happens during programmed cell death (apoptosis) and discuss two examples of how this type of cell death affects the development of a multicellular organism.

this protocol provides a detailed procedure for co-immunoprecipitation (co-ip) to identify protein–protein interactions.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms