How does anthrax invade a host? a. it takes over a cell's dna c. it causes severe allergies b. it kills immune cells that recognize a protein that it produces d. it kills red blood cells near wounds

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.