F. ABO BLOOD TYPE Please Be Sure To Watch The Amoeba Sisters Video On The Multiple Alleles (ABO Blood Types) And The Geneties Of Blood Typing Before Performing These Crosses. The ABO Blood Groups In Humans Are Determined By Multiple Alleles. A Single Gene Can Exist In Any Of Three Allelie Forms: 1. Por I. This Inheritance Of The ABO Blood Type Displays
The Correct Answer and Explanation is :
The ABO blood group system is determined by multiple alleles, specifically three alleles: IA, IB, and i. These alleles control the presence or absence of antigens on the surface of red blood cells, which are responsible for determining an individual’s blood type. The gene for ABO blood type is located on chromosome 9, and each individual inherits two alleles, one from each parent.
- IA and IB are dominant alleles, meaning that if either allele is present, its corresponding antigen will be expressed on the surface of red blood cells.
- i is a recessive allele, meaning that for the blood type to be type O, an individual must inherit two copies of the i allele (one from each parent).
The possible blood types are:
- Type A – This occurs when an individual inherits an IA allele from one parent and either another IA allele or an i allele from the other parent. The presence of the A antigen on the red blood cells defines this blood type.
- Type B – This occurs when an individual inherits an IB allele from one parent and either another IB allele or an i allele from the other parent. The presence of the B antigen on the red blood cells defines this blood type.
- Type AB – This occurs when an individual inherits both an IA allele from one parent and an IB allele from the other parent. This results in both A and B antigens being present on the surface of red blood cells, and AB is a codominant inheritance pattern where both antigens are expressed.
- Type O – This occurs when an individual inherits two i alleles, one from each parent. Since there are no antigens on the surface of the red blood cells, the individual’s blood type is O.
Punnett Square Explanation:
When conducting genetic crosses, you can predict the offspring’s blood type by using a Punnett square. For example, if one parent has blood type AB (IAIB) and the other has blood type O (ii), the possible offspring genotypes will be IAi (Type A) and IBi (Type B). Therefore, the offspring would either have type A or type B blood, but never type AB or O.