Concordant type of twins are

Options

A. Free martins
B. Dizygotic twins
C. Monozygotic twins
D. Both B and C.

Answer

**Step-by-Step Solution:**

1. **Understanding Twin Types**: Begin by recognizing the two main types of twins: monozygotic (identical) and dizygotic (fraternal).

2. **Definition of Concordant Twins**: Concordant twins refer to twins that share similar characteristics, both phenotypically (physical traits) and genotypically (genetic traits).

3. **Identifying Monozygotic Twins**: Monozygotic twins are formed when a single fertilized egg (zygote) splits into two embryos. This results in twins that are genetically identical, hence they are concordant.

4. **Identifying Dizygotic Twins**: Dizygotic twins are formed from two separate eggs fertilized by two different sperm. They are genetically similar but not identical, making them less concordant compared to monozygotic twins.

5. **Conclusion**: Since concordant twins are those that are genetically identical, the correct answer is monozygotic twins.

6. **Final Answer**: Therefore, the answer to the question "Concordant type of twins are" is option C, monozygotic twins.

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