Which blood type could be given as a transfusion for patient with ab blood when the rh factor is unknown?
o+
a+
ab+
ab–

The right answer is AB-.

In humans, the blood group is determined by the substances on the surface of the red blood cells, called antigens. Blood groups are grouped into systems. In the ABO system, there are four possible blood groups: A, B, O, and AB. In the Rh system, the presence or absence of substance "D" on the surface of the red blood cell determines whether Rh is positive (+) or negative (-).

The combination of the two systems allows classification into 8 blood groups: groups: A +, A-, B +, B-, AB +, AB-, O + and O-.

A Rh- subject can only receive Rh- blood, but a Rh + subject can receive Rh + but also Rh- since the latter does not possess rhesus antigen. therefore if we do not know the rhesus of the subjects we can transfuse Rh-blood without risk (Biensur with ABO compatibility).

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.