4. Birds flying south for the winter are demonstrating
5. Muscles that cause a joint to bend are called

Which of the following systems in absorbing oxygen and releases carbon dioxide

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.

Contrast how pollination is different among gymnosperms and angiosperms.