| When you chew your food and swallow it, it rolls down up to your stomach, and when it reaches there, it will start its remaining portion of mechanical digestion. |
| In order for nutrients to be absorbed, food must undergo chemical and mechanical digestion. |
| The seeds most likely to be dispersed are small, hard seeds, which are best able to withstand the mechanical digestion in the birds' gizzard. |
| Chemical digestion involves enzymes whereas mechanical digestion does not. |
| Not only did the more mature specimens lack teeth and seem to have had a beak, they also had rocks in their gullet, called gastroliths, that modern birds use for mechanical digestion. |
| Instead of mechanical digestion, they use filter feeding that sifts through the water while trapping prey in bristles, a skin derivative. |
