What do cells need to do between divisions to make sure that a full set of DNA gets passed on each daughter cell

They need to replicate the full amount of their DNA so that there are two complete copies for each daughter cell to get one.

The "cell cycle" consists of a resting phase or G0 phase followed by Interphase, which is divided into G1, S and G2 phases. The G1 phase prepares the cell to replicate its DNA, the replication of the DNA then takes place in the S phase, and then during the G2 phase the cell prepares to enter the M phase which is when the actual mitosis or cell division happens.

Explanation:

i think that you are smart and you should fit for it out

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!