Question

Describe the structure of the following with the help of labelled diagram.

Nucleus

Answer 1

The nucleus is a double membrane-bound principle cell organelle that contains all genetic information for controlling cellular metabolism and transmitting genetic information.

Nucleus is differentiated into following four parts:

1. Nuclear envelope: A double membrane bound envelope surrounds the nucleus and separates the latter from the cytoplasm.
2. Nucleoplasm: It is clear, non-staining, fluid material present in the nucleus, which contains raw materials (nucleotides), enzymes (DNA/RNA polymerases) and metal ions for the synthesis of RNAs and DNA. The nuclear matrix or the nucleoplasm, is composed of nucleolus and chromatin.
3. Nucleolus: It is a naked, round and slightly irregular structure, which is attached to the chromatin at a specific region. It is a site for active ribosomal RNA synthesis.
4. Chromatin: It has the ability to get stained with certain basic dyes. It is known to be the hereditary DNA protein fibrillar complex. The chromatin fibres are distributed throughout the nucleoplasm.