Welcome to twich22โs page.
Contributor score: 1
Comments ...
Subcomments ...
tyrionwill
how about the choice of D: 1 in 4 have 50% function, which is true. shall 50% function needs transfusion?
+
tyrionwill
In FA, it defines beta thalassemia into minor (HbA2 >3.5%) and major (both HbF and HbA2 go further up), and the major needs transfusion frequently. How can we take this classification based upon quantitive way like in this question? how much percentage of function left does not need a frequent transfusion?
+
azibird
D says one in TWO, not one in FOUR.
+6
hemehero
Is there a way to know that B+B0 will = 25% function. I was stuck between 25% function and 10% function, but couldn't figure out how to reason between the two of them.
+3
neil_simmons
The question says the mother has a mutation known to cause 50% decrease in beta-globin gene function of one allele. So if one allele is working at 50% (B+) and the other allele is working at 0% (B0), then that would mean that particular set of alleles would function at 25%.
+2
twich22
The Key here is the woman has 50% decrease in function "Of one allele". Its a stupid way to word it, But it means that one allele works at 50%, which would be B+. So if you have a B0/B+ offspring, the B0 gives 0% and the B+ works at 50% capacity, so you only have 25% of normal.
+
murad
some one explain this to me please, how come if the mother with his genotype BB+ has 50% function of one allele. while if we get her offspring punnet square we consider the one that has the same genotype as her BB+ of having 75% function??
+
Make a punnett square with a cross of B B+ and B B0; B+ represents 50% function while B0 represents 0% (null) function. So in this case, the husband would have a B B0 genotype while the wife has a B B+ genotype.
Cross of these two will result in the following genotypes; BB, BB0, BB+, B+B0 BB = 100% function, BB+ = 75% function, BB0 = 50% function, B+B0 = 25% function
So the answer will be 1 in 4 have a 25% function given the genotypes.