What is the term for the entire period between one M phase and the subsequent M phase?

The term that describes the entire period between one M phase and the subsequent M phase is interphase. Interphase encompasses several phases of the cell cycle, including the G1 phase (first gap), S phase (synthesis), and G2 phase (second gap), where the cell grows and prepares for division. During interphase, the cell undergoes various critical processes such as DNA replication and preparation of cellular components necessary for mitosis.

In contrast, the other phases mentioned, such as prophase, represent specific stages within the M phase (mitosis), while G1 is only one part of interphase focused on cell growth before DNA replication occurs. Anaphase is a specific phase during mitosis where sister chromatids are pulled apart, thus not reflecting the entirety of the cell cycle. Interphase captures the entirety of activities and preparatory phases leading up to the next mitotic event.