What can be the blood group of offspring when both parents have AB blood group ?

Options

A. AB only
B. A,B and AB
C. A,B,AB and O
D. A and B only

Explanation

To determine the possible blood groups of offspring when both parents have AB blood group, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Alleles of the Parents**:
- Both parents have AB blood group. This means each parent has one allele for A (IA) and one allele for B (IB).
- Thus, the genotypes of both parents can be represented as IAIB.

2. **Set Up a Punnett Square**:
- To find the possible combinations of alleles in the offspring, we can use a Punnett square.
- The alleles from one parent (IA and IB) will be placed on one side, and the alleles from the other parent (IA and IB) will be placed on the other side.

3. **Fill in the Punnett Square**:
- The Punnett square will look like this:

```
IA IB
----------------
IA | IAIA | IAIB |
----------------
IB | IAIB | IBIB |
----------------
```

4. **Determine the Genotypes of Offspring**:
- From the Punnett square, we can see the possible genotypes of the offspring:
- IAIA (Blood group A)
- IAIB (Blood group AB)
- IAIB (Blood group AB)
- IBIB (Blood group B)

5. **List the Possible Blood Groups**:
- The possible blood groups for the offspring are:
- Blood group A (from IAIA)
- Blood group AB (from IAIB)
- Blood group B (from IBIB)

6. **Conclusion**:
- Therefore, the possible blood groups of the offspring when both parents have AB blood group are A, AB, and B. There will be no offspring with blood group O since there are no alleles for O (ii) present in either parent.

### Summary of Possible Blood Groups:
- A
- AB
- B