Select incorrect pairing.

Options

A. Hetersomes-Sex chromosomes
B. Lampbrush chromosomes-Diplotene bivalents
C. Polytene chromosomes - Oocytes of amphibians
D. Heterochromatin - Darkly stained region of chromosome

Answer

To solve the question of selecting the incorrect pairing, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Heterosomes and Sex Chromosomes**:
- Heterosomes are indeed known as sex chromosomes. In humans, males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).
- **Conclusion**: This pairing is correct.

2. **Lambrecht Chromosomes and Diplotene Bivalents**:
- Lambrecht chromosomes are found in the oocytes of amphibians during the diplotene stage of meiosis I. They are bivalent in nature, meaning they consist of paired homologous chromosomes.
- **Conclusion**: This pairing is correct.

3. **Polytene Chromosomes**:
- Polytene chromosomes are not found in the oocytes of amphibians. Instead, they are characteristic of certain organisms, such as two-winged flies (e.g., Drosophila), and are formed through repeated rounds of DNA replication without cell division.
- **Conclusion**: This pairing is incorrect as it incorrectly associates polytene chromosomes with amphibian oocytes.

4. **Heterochromatin and Darkly Stained Regions**:
- Heterochromatin refers to regions of DNA that are densely packed and stain darkly during cell division. These regions are irregularly distributed within the nucleus.
- **Conclusion**: This pairing is correct.

### Final Answer:
The incorrect pairing is **Polytene Chromosomes with Oocytes of Amphibians**.