Briefly describe the flow of energy among organisms in an ecosystem

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

The body is protected against harmful flu viruses by

In which state was more than 100 billion tons of coal mined in 2005?