Final answer:
During cytokinesis, chromosomes are in their single-stranded form as sister chromatids have already separated. A new set of single-stranded chromosomes is enclosed in each newly forming nucleus before the cell fully divides.
Step-by-step explanation:
Chromosomes are composed differently at various stages of the cell cycle. During cytokinesis, the last stage of cell division following mitosis or meiosis, the chromosomes are in their single-stranded form. This is because during anaphase, the sister chromatids separate and move to opposite poles of the cell. Each chromatid is now considered a full-fledged chromosome. In telophase, which occurs just before cytokinesis, the separated chromosomes reach the poles, and new nuclear membranes form around each set.
During cytokinesis itself, the cell's cytoplasm divides to form two new cells, with each cell containing a complete set of chromosomes. Hence, by the end of cytokinesis, each new cell will have single-stranded chromosomes. It is essential to note that these new cells will enter into interphase, during which the DNA will again be in the form of chromatin until it condenses to form chromosomes in preparation for the next cell division.