An abnormal human baby with 'XXX' sex chromosomes was born due to a) Formation of abnormal sperms in the father b) Formation of abnormal ova in the mother c) Fusion of two ova and one sperm d) Fusion of two sperms and one ovum

Options

A. Formation of abnormal sperms in the father
B. Formation of abnormal ova in the mother
C. Fusion of two ova and one sperm
D. Fusion of two sperms and one ovum

Answer

To solve the question regarding the abnormal human baby with 'XXX' sex chromosomes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Condition**: The 'XXX' sex chromosome configuration indicates a condition known as Triple X syndrome or trisomy X. This occurs when a female has an extra X chromosome.

2. **Identifying the Cause**: The question asks for the cause of this chromosomal abnormality. The key to understanding this is to look at how gametes (sperm and ova) are formed.

3. **Gamete Formation**: Normally, during gamete formation (meiosis), each gamete receives one copy of each chromosome. In females, this means that typically, each ovum should receive one X chromosome.

4. **Abnormal Gamete Formation**: In cases of chromosomal abnormalities, such as in the case of Triple X syndrome, it is possible for an ovum to receive two X chromosomes instead of one. This can happen due to errors during meiosis, specifically in the processes of segregation where chromosomes fail to separate properly.

5. **Evaluating the Options**:
- **Option a**: Formation of abnormal sperms in the father - This would not lead to an 'XXX' condition, as sperm contributes either an X or a Y chromosome.
- **Option b**: Formation of abnormal ova in the mother - This is the correct answer, as it can result in an ovum with two X chromosomes.
- **Option c**: Fusion of two ova and one sperm - This is not a typical scenario for human fertilization and does not lead to 'XXX'.
- **Option d**: Fusion of two sperms and one ovum - This is also not a typical scenario and would not result in 'XXX'.

6. **Conclusion**: Based on the analysis, the formation of abnormal ova in the mother is the most plausible explanation for the birth of a baby with 'XXX' sex chromosomes.

### Final Answer:
**b) Formation of abnormal ova in the mother**

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