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 />
The process that occurs before hypothesis is Identifying the variables.
Carbon accumulates oxygen
Animals can be classified into two main groups:vertebrates and invertebrates<span>. The main difference between </span>vertebrates and invertebrates<span> is that</span>invertebrates<span>, like insects and flatworms, </span>do<span> not</span>have<span> a backbone or a spinal column. Examples of</span>vertebrates<span> include humans, birds, and snakes. hope this helped</span>