Question

In general, size of the cells has no relationship to the size of the organism. How do the nerve cells in a rat and giraffe compare in their length?

Answer 1

because nerve cell depends on the location

Answer 2

The evolutionary changes occurred in giraffe, they developed long necks and rest of its body also became massive. So as the nerve cells are also long.This made the giraffe to respond very slowly to the outside environment. In contrast, rats have very short nerve cells (neurons) ,their response to stimuli is so fast.Hence function of the cells related to their size