What must cells do before they perform mitosis? Why must they do this? What happens if this does not occur?

Cells perform DNA replication before mitosis. DNA is replicated because existing cells divide to produce new cells and they need the right instructions for cell division. If cells don't replicate their DNA or don't do it completely, the daughter cell will end up with no DNA or only part of the DNA.

Explanation:

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.