Which of the following is not true concerning the energy harnessed by humans throughout history?
a. early hominids harnessed the least energy, just that of their own bodies.
b. fire let humans increase their energy use tenfold.
c. neolithic farmers were able to harness the energy of animals.
d. modern humans use more than a hundred times the energy of early humans.

Which of the following statements is correct in hour our immune system responds to a potential pathogen? a. the adapted immune system will call on the innate immune system to destroy the pathogen. b. b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c. the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. d. the t-cells in the adapted immune systems are the first to recognize the pathogen vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a. antigen, antibody b. antibody, antigen c. antibody, antibiotic d. antibiotic, antibody