What do the numbers 3 and 4 refer to 3NH4

Which statements correspond to cellular respiration? co2 diffuses passively into the cell. co2 diffuses passively out of the cell. co2 must be pumped out of the cell. o2 diffuses passively when produced inside the cell. o2 diffuses passively when converted to co2. o2 is pumped in and forces co2 out.

Which characteristics are typical of a human population in the postindustrial stage?

Match each symbol with its description.