Human genetic at metaphase may be karyotyped.

Answer

### Step-by-Step Text Solution:

1. **Understanding Metaphase**:
- Metaphase is a stage in cell division (mitosis or meiosis) where chromosomes are highly condensed and aligned at the cell's equatorial plane. This arrangement makes it easier to visualize and analyze the chromosomes.

**Hint**: Remember that metaphase is critical for chromosome visibility due to the alignment and condensation of chromosomes.

2. **Formation of Chromosomes**:
- During metaphase, the chromosomes consist of two sister chromatids joined at the centromere. The synaptonemal complex, which forms during earlier stages of meiosis, helps in the pairing of homologous chromosomes, but it is during metaphase that the chromosomes are most distinct.

**Hint**: Focus on the structure of chromosomes during metaphase, particularly the sister chromatids and their arrangement.

3. **Karyotyping Process**:
- Karyotyping is a laboratory technique that involves staining and photographing chromosomes during metaphase. The images are then arranged in pairs according to size, shape, and number, allowing for the identification of chromosomal abnormalities.

**Hint**: Karyotyping is essential for identifying genetic disorders, so keep in mind the importance of chromosome analysis.

4. **Applications of Karyotyping**:
- Karyotyping can be used to detect genetic diseases, chromosomal abnormalities (like Down syndrome, which is caused by an extra chromosome 21), and to study the genetic makeup of individuals. It can also assist in gene therapy by identifying damaged genes that may need replacement.

**Hint**: Think about how karyotyping can aid in medical diagnoses and treatment strategies.

5. **Chromosome Visibility**:
- The chromosomes are in a condensed state during metaphase, which allows for clear visibility of their structure. This visibility is crucial for accurate analysis and identification of chromosomal features.

**Hint**: The visibility of chromosomes is key to the effectiveness of karyotyping; consider how this impacts genetic research.

### Summary:
Karyotyping is performed during the metaphase stage of cell division because the chromosomes are condensed and aligned, making them easily observable. This technique is essential for identifying genetic disorders and can aid in gene therapy by allowing for the replacement of damaged genes.