Biology · Variation and Genetics
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A man with type A– blood and a woman with type AB+ blood have a child. Which blood type is impossible for that child to have?
- A
A-
- B
B-
- C
AB+
- D
O-
The ABO blood type system is based on the presence of two antigens (A and B) on the surface of red blood cells and two antibodies (anti-A and anti-B) in the plasma. In this scenario, the mother has both A and B antigens on her red blood cells (AB blood type) and the father has only A antigen (A- blood type). When these two blood types are combined, the possible blood types for their child are A, B, AB, or O. However, the child cannot inherit the B antigen from either parent because the father does not have it, so the child cannot have an AB blood type. Additionally, the child cannot have type O blood type because both parents must contribute an O allele, which means the child must inherit two O alleles. Since the father does not have an O allele, the child cannot have type O blood type. Therefore, the child must have either A or B blood type.
It is possible for the child to have type A- blood type. The father has type A- blood type, which means he has one A allele and one negative Rh factor allele. The mother has type AB+ blood type, which means she has both A and B alleles and a positive Rh factor allele. When these two blood types are combined, the child could inherit one A allele and one negative Rh factor allele from the father, and either an A or B allele and a positive Rh factor allele from the mother. This would result in the child having type A- blood type.
The child can have type B- blood type. The child could inherit one B allele and one negative Rh factor allele from the mother, and one negative Rh factor allele from the father. This would result in the child having type B- blood type.
The child can have type AB+ blood type. The father has type A- blood type, which means he has one A allele and one negative Rh factor allele. The mother has type AB+ blood type, which means she has both A and B alleles and a positive Rh factor allele. When these two blood types are combined, the child could inherit one A allele and one B allele from the mother, and one negative Rh factor allele from the father. This would result in the child having type AB- blood type. However, the child could also inherit the positive Rh factor allele from the mother, which would result in the child having type AB+ blood type.
The ABO blood type system is based on the presence of two antigens (A and B) on the surface of red blood cells and two antibodies (anti-A and anti-B) in the plasma. In this scenario, the mother has both A and B antigens on her red blood cells (AB blood type) and the father has only A antigen (A- blood type). When these two blood types are combined, the possible blood types for their child are A, B, AB, or O. However, the child cannot inherit the B antigen from either parent because the father does not have it, so the child cannot have AB blood type. Additionally, the child cannot have type O blood type because both parents must contribute an O allele, which means the child must inherit two O alleles. Since the father does not have an O allele, the child cannot have type O blood type. Therefore, the child must have either A or B blood type.
Tagged under Biology · Variation and Genetics · 2021