Amismatch of blood types during a transfusion is dangerous because preformed antibodies in the recipient's blood will bind and clump (agglutinate) the donated cells antibodies in the donor's plasma will attack and kill the recipient's healthy blood cells white blood cells from the donor's blood cause inflammation clotting factors in the donor's blood will cause unwanted clots known as thrombus

The answer is  Preformed antibodies in the recipient's blood will bind and clump the donated cells.

Every person’s blood type is determined by the antigen on their blood cells. If a person is of blood group A, then they have antigen A in their blood cells. Additionally, the same person will have antibodies to the alternative antigen, i.e in our case the person with blood group A will have antibodies for antigen B. Therefore if a patient with blood group A is transfused with blood group B blood, then the antibodies in the patient will bind to the transfused blood cells and cause agglutination.

preservation because he preserves part of the land and preserves means save

explanation:

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides