EVERYDAY SCIENCE

Detailed explanation-1: -Answer and Explanation: Myelinated nerve fibers are b) White matter. Myelin sheaths are composed of lipids that are white in color. Therefore, when structures of the nervous system are described as being composed of white matter, it is because the neural axons are myelinated.

Detailed explanation-2: -Myelinated fibers make up the white matter in the CNS, while cell bodies and unmyelinated fibers make the gray matter. The unmyelinated regions between the myelin segments are called the nodes of Ranvier. In the peripheral nervous system, the myelin is produced by Schwann cells.

Detailed explanation-3: -White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts.

Detailed explanation-4: -Besides this group of neuronal cells, the axons of grey matter are not heavily myelinated, unlike white matter, which contains a high concentration of myelin.

Detailed explanation-5: -The part of the brain and the spinal cord, where myelinated neurons are present in abundance is called white matter and the part where the cell body and non-myelinated neurons are present is called grey matter.