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Question 18 in Biology --> Incorrect Answer Explanation

Posted: Sun Jun 30, 2013 2:20 am
by Ncassidy121
18. The genetic basis of human blood types includes recessive (Zo) and codominant alleles (ZA and ZB). Determine which of the following genotypes produce blood that agglutinates when combined with type O serum:
I. ZAZA
II. ZAZB
III. ZAZO

A. I only
B. III only
C. I and II only
D. I and III only
E. I, II and III


Your answer: Unanswered
Correct answer: E
Discuss this question
Explanation:

BIO 1.2.2, BIO 3

An antibody-antigen interaction involving serum and red blood cells leads to clumping or agglutination. Type O blood is the "universal donor" because the red blood cells have no antigens. However, type O serum contains anti-A and anti-B antigens. I, II and III contain red blood cells with either some A or B or both antigens, thus resulting in antibody-antigen interaction with type O serum.

I believe there is an error with this question's answer explanation. The answer states "However, type O serum contains anti-A and anti-B antigens". Shouldn't the answer be that type o serum contains type A and B anti bodies? I could be wrong, but this seems a bit shifty.

Re: Question 18 in Biology --> Incorrect Answer Explanation

Posted: Mon Nov 25, 2013 2:18 pm
by ryjurilla
The answer is correct but the explanation indeed has a typo, and should read "antibody" as you mentioned, and not "antigen". We have updated the question. Good pick up.

Re: Question 18 in Biology --> Incorrect Answer Explanation

Posted: Fri Aug 08, 2014 5:59 am
by keithlacon
Yes O serum contains anti-A and anti-B antigens, but I would say still before using it, consult the doctor whether it will be safe to use it.