Question

the table shows the allele combinations of various blood groups found in humans
which conclusion is best supported by the information in the table?
allele b is dominant over allele a
allele a is dominant over allele b
both alleles a and b are dominant over allele i
both alleles a and b remain unexpressed when present together

Explanation:

Looking at the table, when \(I^{A}\) or \(I^{B}\) is paired with \(i\) (e.g., \(I^{A}i\) gives blood - group A and \(I^{B}i\) gives blood - group B), the \(I^{A}\) and \(I^{B}\) alleles are expressed. This shows that \(I^{A}\) and \(I^{B}\) are dominant over \(i\). When \(I^{A}\) and \(I^{B}\) are together (\(I^{A}I^{B}\)), both are expressed (blood - group AB), so they are codominant with each other.

Answer:

Both alleles A and B are dominant over allele i.