Which of the following is absent in nerve cell? 

The correct answer is Centriole.

Key Points

• Centrioles are absent in nerve cells (neurons).
• Centrioles play a crucial role in cell division, particularly in the formation of the spindle fibres that segregate chromosomes during mitosis and meiosis.
• Nerve cells, once mature, generally do not undergo division.
• This characteristic is partially why nerve cell damage in adults is often irreversible; without the ability to divide, damaged neurons cannot be replaced through the body's natural processes.

Additional Information

• Nucleus: Nerve cells contain a nucleus. The nucleus houses the cell’s genetic material and is responsible for controlling the cell’s activities.
• Mitochondria: Mitochondria are present in nerve cells and play a critical role in energy production, providing the energy necessary for nerve cell function, including neurotransmission.
• Ribosome: Ribosomes are present in nerve cells and are involved in protein synthesis. Proteins are essential for the structure, function, and regulation of the body's tissues and organs, including those in nerve cells.