Mendelian disorders can be traced in a family by

Options

A. pedigree analysis
B. cytological observaation
C. gene mapping
D. DNA fingerprinting

Answer

### Step-by-Step Solution:

1. **Understanding Mendelian Disorders**:
- Mendelian disorders are genetic conditions that follow Mendel's laws of inheritance. Examples include hemophilia and sickle cell anemia.

2. **Identifying the Techniques for Tracing Disorders**:
- The question asks how we can trace these disorders in a family. The options provided include pedigree analysis, cytological observation, gene mapping, and DNA fingerprinting.

3. **Explaining Pedigree Analysis**:
- Pedigree analysis is a method used to study the inheritance of traits in several generations of a family. It involves creating a family tree that outlines the occurrence of a specific trait or disorder among family members.

4. **Analyzing the Other Options**:
- **Cytological Observation**: This involves studying chromosomes but does not specifically trace Mendelian disorders in families.
- **Gene Mapping**: This technique locates genes on chromosomes but is not primarily used for tracing inheritance patterns in families.
- **DNA Fingerprinting**: This is a technique used mainly for forensic purposes and does not trace Mendelian disorders.

5. **Conclusion**:
- The correct method to trace Mendelian disorders in a family is through **pedigree analysis**. This method allows us to visualize how traits are passed down through generations and identify carriers of genetic disorders.