Balbiani rings are found in

Options

A. polytene chromosomes
B. diplotene chromosomes
C. Z-DNA
D. Lampbrush chromosome

Answer

**Step-by-Step Solution:**

1. **Understanding Polytene Chromosomes:**
- Polytene chromosomes are specialized chromosomes that are formed by the somatic pairing of homologous chromosomes. This means that during certain developmental stages, homologous chromosomes align and replicate multiple times without separating, leading to a thickened, multi-stranded appearance.

2. **Characteristics of Polytene Chromosomes:**
- These chromosomes are always in a permanent prophase stage, which means they do not progress to the next stages of cell division. They are primarily found in the salivary glands of certain insects, hence they are also referred to as salivary chromosomes.

3. **Identifying Balbiani Rings:**
- Within polytene chromosomes, there are noticeable swellings known as chromosome puffs. The larger swellings among these are called Balbiani rings. These rings are formed when the DNA strands within the polytene chromosomes uncoil and become active, leading to the production of multiple copies of mRNA.

4. **Conclusion:**
- Based on the characteristics and functions of Balbiani rings, we conclude that they are found in polytene chromosomes. The other options provided (diplotene chromosomes, Z-DNA, and lampbrush chromosomes) do not contain Balbiani rings.

**Final Answer:**
Balbiani rings are found in polytene chromosomes.

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