Early prophase of a diploid cell has_____ sets of chromosomes; telophase of a diploid cell has ____ sets of chromosomes

To understand the number of chromosome sets (ploidy) during different stages of cell division, let us break down the concepts of diploidy and the phases of mitosis.

1. Understanding Diploid Cells:
A diploid cell (represented as $2n$) contains two complete sets of chromosomes, one set inherited from each parent. For example, in humans, a diploid cell has 23 pairs of chromosomes, which equals 46 chromosomes in total (2 sets of 23).

2. Chromosomes in Early Prophase:
During the S phase of interphase (prior to prophase), DNA replication occurs. Each chromosome is duplicated to form two sister chromatids joined at the centromere. However, the number of chromosome sets does not change; the cell is still considered diploid ($2n$). Therefore, in early prophase, the cell still contains 2 sets of chromosomes.

3. Chromosomes in Telophase:
During mitosis, the duplicated chromosomes are aligned and separated. In anaphase, the sister chromatids are pulled apart to opposite poles of the cell, with each chromatid now becoming an individual chromosome. During telophase, nuclear membranes reform around these two separate groups of chromosomes at each pole. Since mitosis divides the genetic material equally to ensure that each new daughter nucleus is identical to the parent nucleus, each forming nucleus in telophase receives a complete diploid set of chromosomes. Thus, each of the forming nuclei in telophase contains 2 sets of chromosomes.

Combining these facts:
- Early prophase of a diploid cell has 2 sets of chromosomes.
- Telophase of a diploid cell has 2 sets of chromosomes (in each forming nucleus).

Therefore, the correct option is 2;2.