converting food into smaller molecules
American prairie, bison and badgers don't live in any of the other options naturally.
<span> unicellular ciliates, </span>
I know one is the immune system
According to Charles Darwin's theory of evolution by natural selection, organisms that possess heritable traits that enable them to better adapt to their environment compared with other members of their species will be more likely to survive, reproduce, and pass more of their genes on to the next generation.
