O blood has no<span> antigens and is referred to as </span>universal donor blood<span>, so that </span>will<span> not cause a reaction. So, a </span>person<span> with </span>AB blood has<span> all of the antigens that are possible, and an O negative </span>person has no<span> antigens that would cause a reaction.</span>
Cows are consumers because they do not make their own food from the sun, they must eat other organisms (grass).
autotrophs automatically make their own food, so they are producers.
