What is the longest phase of the cell cycle characterized by growth and preparation for division?

The longest phase of the cell cycle, characterized by growth and preparation for division, is interphase. Interphase encompasses several stages where the cell undergoes growth, development, and preparation for mitosis.

During interphase, which comprises the G1 phase, S phase, and G2 phase, the cell increases in size, replicates its DNA, and prepares the necessary components for cell division. G1 phase involves cellular growth and normal metabolic processes, while the S phase is specifically for DNA synthesis, where each chromosome is duplicated. The G2 phase involves further growth and preparation for mitosis, including the synthesis of proteins and organelles required for division.

Although both G1 and G2 are part of interphase, they are not as extensive in duration as interphase as a whole. Therefore, interphase is the correct identification of the longest phase where the cell is not only growing but also actively preparing for the subsequent mitotic division.