First, I would break the cell cycle into its main parts and dedicate a stanza, or a group of lines, to each step of the process. Since the cell cycle has four distinct phases, you could write three to four lines about each of the four phases: G1, synthesis, G2 (interphase), and mitosis.
You could also consider giving the poem a simple rhyme scheme to make it sound more like a poem. For example, if you had three lines for each one of the stanzas about the phases, you could make the first and third line of each stanza rhyme.
In mitosis, the cell divide,
A check point, metaphase,
Then they split, it's been one wild ride!