Question

Inheritance of blood group is a condition of
1. Co- dominance
2. Incomplete dominance
3. Multiple allelism
4. Multiple gene
A) $1,2$
B) $2,4$
C) $2,3$
D) $1,4$
E) $1,3$

Answer 1

The blood types were discovered by Karl Landsteiner, a biologist. He was a physician from Austria. The blood groups are defined, as we all know, based on antigenic compounds on the surface of red blood cells (RBCs) and the presence or absence of antibodies. Antigens might be carbohydrate molecules, proteins, glycoproteins, or glycolipids. This is largely determined by the blood grouping system. One may argue that the ABO and Rh blood group systems are the most important blood group systems for determining a person's blood type and appropriateness for blood transfusion.

Complete answer:
Option A: Our blood type, like our eye or hair colour, is inherited from our parents. Each biological parent passes one of two ABO genes to their offspring. The O gene has a recessive inheritance pattern, whereas the A and B genes have a dominant inheritance pattern.
So option A is not correct.
Option B: A, B, AB, and O are the four blood groups that humans have. As a result, numerous alleles and codominance can be seen in human blood grouping genetics. Pseudodominance is a condition in which a recessive characteristic is inherited as if it were a dominant trait.
So option B is not correct.
Option C: Humans are divided into four blood groups: A, B, AB, and O. A collection of three multiple alleles found on chromosome $9$ is claimed to control blood types. The ABO blood group is said to be an excellent example of codominance.
So option C is not correct.
Option D: When the dominant allele is not completely dominant over the recessive allele, a heterozygous phenotype that is a mix of dominant and recessive is produced. When more than one gene governs a trait, it is said to be under the influence of multiple genes. Human blood types are an example of codominance and multiple allele inheritance.
So option D is not correct.
Option E: Incomplete dominance occurs when the dominant allele is not totally dominant over the recessive, resulting in a heterozygous phenotype that is a mix of dominant and recessive. A trait is said to be under the control of several genes when it is governed by more than one gene. The inheritance of human blood groups is an example of codominance and multiple alleles. Three alleles of the gene "I," notably ${I^A},{\text{ }}{I^B}$, and ${I^O}$, control it. ${I^A}$ and ${I^B}$ are codominant, however allele "${I^O}$" is recessive in both "${I^A}$" and "${I^B}$."There are a total of six genotypes and four phenotypes as a result of this- A (${I^A}{I^A}$ and ${I^A}{I^O}$), B (${I^B}{I^B}$ and ${I^B}{I^O}$), AB(${I^A}{I^B}$) and O (${I^O}{I^O}$)”.

So option E is the correct answer.

Note:
The set of functional relationships between genes is referred to as genetic interactions. The presence and absence of antibodies, as well as the inherited antigenic compounds on the surface of RBCs, are used to define blood types. Human blood is divided into four groups: A, B, AB, and O. The blood types are determined by a set of three multiple alleles found on chromosome $9$. The blood type-controlling genes have been given the letter i. It stands for isohemagglutinin.