Question

why is it important to know a persons rhesus factor before a blood transfusion?
a patient who is rh+ can receive only rh- blood.
a patient who is rh- can receive only rh+ blood.
a patient who is rh+ can receive only rh+ blood.
a patient who is rh- can receive only rh- blood.

Explanation:

The Rh factor (Rhesus factor) is an important aspect of blood typing. A person with Rh- blood has antibodies against Rh+ blood. If an Rh- person receives Rh+ blood, their immune system will attack the Rh+ blood cells. However, an Rh+ person can receive Rh- blood (as they don't have antibodies against Rh-). So, for a safe blood transfusion, it's crucial that an Rh- patient receives only Rh- blood.

Answer:

A patient who is Rh– can receive only Rh– blood.