Which of the following about secondary succession is not true?

a.) it occurs in ecosystems without soil.
b.) it occurs in ecosystems that are already established.
c.) it reduces the number of species in an ecosystem.
d.) it is initiated by a disruptive event.

The part of a desired plant inserted into rootstock during grafting is called the

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

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?