I need help with this biology stuff

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

Connection compare and contrast genetic engineering to the process of natural selection. select all statements that are true.

Which nucleotide component contains nitrogen