Hetero-chromatin is :-

Options

A. Darkly stained part of chromatin
B. Lightly stained part of cristae
C. Lightly stained part of grana
D. Scattered Lobes in cytoplasm

Answer

**Step-by-Step Solution:**

1. **Understanding Chromatin**: Begin by defining what chromatin is. Chromatin is a complex of DNA and proteins found in the nucleus of eukaryotic cells. It exists in two forms: heterochromatin and euchromatin.

2. **Identifying Heterochromatin**: Heterochromatin is one of the two types of chromatin. It is characterized by its dense packing and is generally not transcriptionally active. This means that genes located in heterochromatin are usually not expressed.

3. **Staining Properties**: Heterochromatin can be identified by its staining properties. It appears darkly stained under a microscope due to its compact structure, which makes it denser than euchromatin.

4. **Contrasting with Euchromatin**: In contrast, euchromatin is lightly stained and is the form of chromatin that is actively involved in transcription, meaning it contains genes that are being expressed.

5. **Conclusion**: Based on the characteristics and properties discussed, heterochromatin is defined as the densely packed, darkly stained form of chromatin that is generally transcriptionally inactive.

**Final Answer**: Heterochromatin is the densely packed, darkly stained form of chromatin that is transcriptionally inactive.

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