Which form of natural selection in polygenictraits results in the creation of two distinct phenotypes

The picture shows a fishing technique called trawling. how might trawling affect marine biodiversity

Ineed to get this test done which of the following statements is correct in hour our immune system responds to a potential pathogen? a.) the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. b.) b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c.) the adapted immune system will call on the innate immune system to destroy the pathogen. d.) the t-cells in the adapted immune systems are the first to recognize the pathogen

What substance acts to prevent sudden ph changes in bodily fluids?