There are three different alleles A, B, O
<span>These produce four different phenotypes A, B, AB, O
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The blood vessels shrink so that less blood with leak out of the wound, platelets ( tiny cells in the blood) stick together around the wound which stop the bleeding (like patching a leak). The blood proteins and platelets join together and form a clot, the clot acts like a mesh to stop the bleeding.
Scoring goals is often helpful
