Antigenic variation is the change occurs in antigenic property of the pathogen. In antigenic variation, a pathogen does changes in its surface protein or carbohydrate so that the immune system of the host is not able to recognize the pathogen.
This antigenic variation is very much beneficial to pathogens because it gives advantage to the pathogen to infect the host again and again without being recognized by immune cells and to increase in number.
A recombination of avian and human influenza virus in a host like pig created a new version of the influenza virus which became very endemic worldwide is a classic example of antigenic shift. M. tuberculosis evades immune response by doing antigenic shift it's membrane and cause tuberculosis.
False, I'd say. Mammals usually adapt based on environment. Now, I know predators are "apart" of the environment, but I don't think that'd be it. I'd bet more money on saying mammals evolve based on environment adaptation. Sorry if I didn't answer your question or if I didn't get my point across well.
They are considered nonrenewable resources because once they are used, they are gone forever, and we are using way more than the Earth can produce. Your answer would be B!
