Question

Which of the following have the nerve cell?
a. A rabbit
b. A cockroach
c. A mushroom
d. Both A and B

Answer 1

Hint: Nerve cells are also called neurons. Nerve cells are the active and important components of the nervous system. Nerve cells communicate with each other and also with the other cells through nerve impulses which permits the effector organs to give a response to the proper stimuli.

Complete answer:
Every nerve cell or neuron is made up of many parts that make them function properly. Many organisms have nerve cells whereas some others lack nerve cells. Hydra has a nerve cell but lacks a brain. The length of the nerve cell body is 0.1 mm.

- The nervous system is composed of nerve cells or neurons in the animals. Cockroach and rabbit are the animals that consist of a nerve cell. Nerve cell function in the passage of impulses and communication. In cockroaches, the nervous system is spread throughout the body.
- Nerve cells in insects live in a controlled chemical environment.
- A mushroom is a fungus. It does not contain any kind of nerve cell or neuron or we can say a nervous system.

Hence, the correct answer is option (D).

Additional information:
> Neurons are composed of:
- Cell body
- Axon
- Nodes of Ranvier
- Dendrites
- Myelin sheath cells
- Axon terminal bundle.

> Nerve cell also contains different types of organelles as like any other type of cell in the animals to keep the nerve cell alive and permit it to remain functional.

> Nerve cells contain organelles such as a nucleus, nucleolus, Golgi bodies, endoplasmic reticulum, and the mitochondria.

> These organelles play various roles and contribute to the appropriate functions of the neuron.

Note: Nerve cells can be explained as receivers and transmitters of information that permit an organism to respond properly. The basic functional unit of the nervous system is the nerve cell or neuron. The cell body of the nerve cell is known as soma that contains the nucleus. Soma is also called a perikaryon.