Which of the following is not an event in the cell cycle?
a. diffusion
c. mitosis
b. interphase
d. growth phase

Diffusion is NOT an event in the cell cycle.

Mitosis is the reproduction of somatic cells and is the basis of the cell cycle.

Interphase occurs at the very beginning of the cell cycle when the cell copies its DNA in preparation for mitosis.

Growth phase (often abbreviated G-phase) takes place during interphase when the cell develops organelles and copies genetic material.

Diffusion is the movement of materials down a concentration gradient and is not directly related to the cell cycle.