Question 18 in Biology --> Incorrect Answer Explanation

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Ncassidy121
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Joined: Sat Jun 22, 2013 4:28 am

Question 18 in Biology --> Incorrect Answer Explanation

Post 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.
ryjurilla
Posts: 9
Joined: Wed Jun 12, 2013 6:28 am

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

Post 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.
keithlacon
Posts: 1
Joined: Fri Aug 08, 2014 5:51 am
Location: USA

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

Post 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.
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