The Treg cell destroys the Tc or Th cell rather than the Cell presenting self antigen because the Treg cell needs to: destroy T cells with receptors that respond to self-antigen. avoid reacting itself to self-antigen passed along by the Cell presenting self-antigen. destroy the self antigen, and it must destroy the cell in order to do this. preserve the cell in the middle that is presenting self-antigen.

What happens when water’s salinity increases? mass decreases. freezing point decreases. buoyancy of objects decreases. the amount of dissolved minerals decreases.

Match the following terms and definitions. 1. species that are adapted to live in equilibrium at carrying capacity population density 2. population growth that reaches equilibrium and carrying capacity population 3. death rate mortality 4. birth rate k-selected 5. a group of interacting individuals of the same species within the same geographic area natality 6. the number of organisms living in a particular area logistic growth

Which of the following matches the organisms described with the correct domain? a. archaea--multicellular, eukaryotic organisms that do not have cell walls b. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sources c. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycan d. bacteria--unicellular, eukaryotic organisms that always lack cell walls