live on the blood or tissue of other organisms.
The type of teeth seen in are usually broad and flat.
Some animals have specialized cells that absorb food, break it down internally, and pass the nutrients to other cells in a process called .
have some tissues, such as cell walls, which require special structures like rumen to break down in the digestive system.
Gas exchange involves the absorption of into the bloodstream and the release of CO2 waste.
Aquatic animals have specialized structures called that allow for oxygen to be absorbed into the bloodstream directly from water as it passes through.
Insects typically have circulatory systems.
Ammonia must be converted into urea in the to be excreted later in mammals as urine.

Recently, crops of vegetables such as lettuce and green onions have been contaminated, while they are still on the farm, with bacteria that cause food poisoning. how will science influence the way the government responds to prevent an increase in food-borne diseases? because science has shown that lettuce and green onions are not nutritionally valuable, the government may pass laws that ban the sale of lettuce and green onions. because science has shown that there is no way to prevent bacterial contamination, the government may pass laws that punish businesses that buy lettuce and green onions. because science has shown that the washing of hands prevent the spread of infectious diseases among people, the government may pass laws that require hand washing by everyone who handles food. because science has shown there are ways to find the source of the contamination, the government may pass laws that require farm practices that reduce the contamination of lettuce and green onions.