Explanation:
Cave lions, sabre-toothed cats, cave bears, giant deer, woolly rhinoceroses, and woolly mammoths were prevailing species of the Quaternary period. Without the dinosaurs, plant life had an opportunity to flourish during the Cenozoic era.
Answer:
The nervous system has two main parts:
The central nervous system is made up of the brain and spinal cord.
The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
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So the cells can react to the changes, and so that specialized cells can perform certain functions