PLEASE HELP ASAP

A specific immune response begins when a white blood cell comes in contact with an antigen (any substance that the immune system does not recognize as part of the body). What external factor typically triggers a specific immune response?

A. an invasion of a microorganism from the external environment
B. a fluctuation of the external air pressure
C. a large release of adrenalin by the endocrine system
D. a change in the external temperature

Cultures of the lake of the ozarks water samples were grown on enrichment media for identification. however, these organisms are present to some degree in all samples. an important question from a clinical perspective is whether or not there is a significant increase in the fecal coliform populations that would put people's health at risk. if you were part of the team investigating this outbreak, how would you best enumerate the fecal coliform threat? view available hint(s) cultures of the lake of the ozarks water samples were grown on enrichment media for identification. however, these organisms are present to some degree in all samples. an important question from a clinical perspective is whether or not there is a significant increase in the fecal coliform populations that would put people's health at risk. if you were part of the team investigating this outbreak, how would you best enumerate the fecal coliform threat? direct microscopic counts filtration count culture serial dilution count culture plate count culture

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from

Describe the layers of the suns atmosphere?