write a note on nucleus
Answers
Answer:
Nucleus is the largest cellular organelle, surrounded by a double membrane nuclear envelope. The outer membrane is continuous with the membranes of endoplasmic reticulum. At certain intervals, the two nuclear membranes have nuclear pores with a diameter of about 90 nm. These pores permit the free passage of the products synthesized in the nucleus into the surrounding cytoplasm.
Nucleus contains DNA, the repository of genetic information. Eukaryotic DNA is associated with basic protein (histones) in the ratio of 1 : 1, to form nucleosomes. Humans have 46 chromosomes, compactly packed in the nucleus. The nucleus of the eukaryotic cell contains a dense body known as nucleolus. It is rich in RNA, particularly the ribosomal RNA which enters the cytosol through nuclear pores. The ground material of the nucleus is often referred to as nucleoplasm. It is rich in enzymes such as DNA polymerases and RNA polymerases.
Answer:
The nucleus is a double-membraned organelle that contains the genetic material and other instructions required for cellular processes. It is exclusively found in eukaryotic cells and is also one of the largest organelles.
A few functions of the nucleus are:
- It includes the cell’s hereditary information and measuresthe cell’s growth and reproduction.
- It is responsible to regulate and coordinate different life processes of the cell
- Producing two identical copies of the body or host is the first step in cell division, where every new cell will get its own set of instructions.
- The nucleus is the site of transcription. Transcription produces different types of RNA from DNA. Transcription would be a lot like creating copies of individual pages of the human body’s instructions which may be moved out and read by the rest of the cell.