How are sugar molecules in living things classified? as proteins
as nucleic acids
as
lipids
as carbohydrates

What was the land like over 500 million years ago? what was under the sea?

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Cells destroy body cells infected by a virus or bacteria. killer t t memory t none of the above