Which of the following describes a relationship of mutualism?

a. a tapeworm latches itself in the intestines of a rat, feeding off all the nutrients eaten by the rat.
b. a polar bear catches a seal for dinner.
c. birds feed off the insects that are stirred up from the grasses as cattle move through.
d. oxpecker birds eat parasitic ticks off the backs of zebras

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna.nothing should be altered.the ph should be decreased.the temperature should be raised.

What is a group of organisms called

Explain what role the narrator believes he is playing in telling the story. describe how this belief will affect the story. your answer should be at least 250 words.