<span>The brain stem is closest to the spinal cord.</span>
All plant and animal groups existing together and the physical factors with which they interact compose an ecosystem<span>.</span>
I think The second step of cellular respiration is the Kreb's cycle and it occurs in mitochondrial matrix.
First step of cellular respiration is glycolysis and it occurs in the cytoplasm of a cell.
I am not really confident about my answer.
If I am wrong please correct me. <span />
Because most waste produced in the cell is toxic when it accumulates.
Hope this helps!
