If a cell has 24 chromosomes before s phase and undergoes one normal cycle of mitosis and cytokinesis, how many chromosomes will each new daughter cell have?

The correct answer is: 24 chromosmes.

Mitosis is the cell division of somatic cells (all cells except gametes) in which mother cell produce two identical daughter cells with the same number of chromosomes as she had.

During the S phase of interphase, replication occurs and the genetic material of a cell is duplicated. There are still 24 chromosomes but they exist in a X shape structure-two sister chromatids (genetically identical). So, there are 24 chromosomes, but 48 chromatids. Sister chromatids separate during the anaphase of mitosis and each chromatid is then considered a separate, individual chromosome. After division and cytokinesis, the normal chromosome number is restored to the cell.  

i am going to guess that it is co2.