Answer:
<h2>CNS- Spinal cord
</h2><h2>PNS- spinal nerve
</h2>
Explanation:
The nervous system divide into two main subdivisions:
i) the central nervous system and
ii) the peripheral nervous system
1. The CNS is comprised of the brain and spinal cord means the brain and spinal cord make up the central nervous system.
2 The Peripheral Nervous System(PNS) contains only nerves (like spinal nerve),
It further divides into somatic and autonomic nervous systems.
The layers are older towards the bottom and you get towards the top
Bauplan is the assembly of the body structure which is common in the organisms belonging to the same phylum. The Same bauplan determines that a body part of the organisms are same and they will be in the same phylum in the Evolution also. Bauplan includes symmetry, segmentation, and limb disposition.