Final answer:
The presence of homologous chromosomes in anaphase I of meiosis I is a key difference from mitosis, where sister chromatids separate instead, which is indicated in the model provided.
Step-by-step explanation:
Mitosis and meiosis are both types of nuclear division in eukaryotic cells, but they have significant differences. One way to distinguish between them is the behavior of the chromosomes during anaphase. During anaphase of mitosis, sister chromatids separate and move to opposite poles of the cell, which results in two genetically identical daughter cells, each with the same number of chromosomes as the original cell.
In contrast, during anaphase I of meiosis, homologous chromosomes, rather than sister chromatids, are pulled apart. This results in the genetic material being halved, which is significant for gamete formation in sexual reproduction. Therefore, the correct answer to the student's question, supported by the model, is a) Presence of homologous chromosomes in anaphase I, as this indicates the reduction division characteristic of meiosis I, and it contrasts with mitosis where such a reduction does not occur.