[Community Puzzle] Blood Types


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Created by @java_coffee_cup,validated by @Pyoroalb,@Deltaspace and @Crypticsy.
If you have any issues, feel free to ping them.

I encounter a problem of understanding between the statement of this exercise and the validators.

For example, the statement on rhesus says:
++ = Rh +
+ - = Rh +
- - = Rh-

So if I understand correctly, with the following line:
A- O +?
Since the parents are rhesus - and +, the child should be +.
However, the solution expects that the child can be + or -.
(expected solution: A+ A- O+ O-)

Similarly, in the 3rd test validator, the first line is:
? O- B-
Do we agree that the parent can only be rhesus - if we want the child to be rhesus -?
However, the solution expects that the parent can be + or -.
(expected solution: AB+ AB- B+ B-)

Could someone enlighten me?

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Each person has two genes and if either are + then they are Rh+. They pass one of the two genes onto the child meaning a parent with ± genes is Rh+ but can create a Rh- child.


First case:
A− can be AO−− or AA−−.
O+ can be OO++ or OO+−.
Second case:
O− can only be OO−−.
B− can be BB−− or BO−−.

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This quoted statement is not true.

The O- parent has Rh genes (- -).
The other parent can have either (+ -) or (- -) genes in Rh.

While you know that (- -) and (- -) parents will have child of (- -),
it is also possible for a (+ -) parent and a (- -) parent to have a child of (- -) in Rh.

1 Like

Would like to say I very like puzzles which can bring some new general knowledge.
Perfect example here: by laziness I never tried to understand the basic of blood type. Now it’s done :stuck_out_tongue:
Thanks for that, java_coffe_cup & CG.