The answers is the symptoms can change with age
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Answer:The answer is spinal cord
Explanation:
The central nervous system consists of the brain and the spinal cord.
The brain is the most highly specialized organ, and is protected by the skull or cranium, while the spinal cord is made up of soft tissue which runs from the medulla oblongata to the tail region. It is protected by the bones of the vertebral column.
The spinal cord acts as a PATHWAY between spinal nerves and the brain.
The correct answer is option A, that is, blood.
Cell theory in biology refers to the universally acknowledged scientific theory that living species are constructed of cells, that is, they are the basic fundamental and structural unit of all species, and that all the cells arises from the pre-existing cells. The theory is credited to Schwann and Schleiden. The three postulates of the theory are:
1. All living species comprises of one or more cells.
2. Cell originate from the pre-existing cells.
3. The cells is the fundamental unit of organization and composition in organisms.