Which of the following characteristics represent 'Inheritance of blood groups' in humans?
a. Dominance
b. Co-dominance
c. Multiple allele
d. Incomplete dominance
e. Polygenic inheritance

Options

A. (a), (c) and (e)
B. (b), (d) and (e)
C. (a), (b) and (c)
D. (b), (c) and (e)

Answer

To determine which characteristics represent the inheritance of blood groups in humans, we need to analyze the options provided in the context of blood group inheritance.

### Step-by-Step Solution:

1. **Understanding Blood Groups**:
- The human blood group system consists of A, B, AB, and O types. This system is based on the presence of specific antigens on the surface of red blood cells.

2. **Identifying the Alleles**:
- The alleles responsible for the blood groups are:
- IA (for blood group A)
- IB (for blood group B)
- IO (for blood group O)

3. **Multiple Alleles**:
- Since there are more than two alleles (IA, IB, IO) for a single trait (blood group), this is an example of **multiple alleles**. Therefore, option **c** is correct.

4. **Dominance**:
- The IA and IB alleles are both dominant over the IO allele. This means that if either IA or IB is present, the corresponding blood group will be expressed. Hence, option **a** (dominance) is also correct.

5. **Co-Dominance**:
- When both IA and IB alleles are present (as in blood group AB), both alleles are expressed equally. This phenomenon is known as **co-dominance**. Therefore, option **b** is also correct.

6. **Exclusion of Other Options**:
- **Incomplete dominance** (option d) does not apply here as there is no blending of traits in blood groups.
- **Polygenic inheritance** (option e) also does not apply since blood groups are determined by a single gene with multiple alleles, not multiple genes.

### Conclusion:
The characteristics that represent the inheritance of blood groups in humans are:
- a. Dominance
- b. Co-dominance
- c. Multiple alleles

### Final Answer:
The correct options are **a, b, and c**.

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