Answer:
One significant difference between a sperm cell and the cells in the developing fetus is that a sperm cell is a specialized reproductive cell carrying genetic material from the father, while the cells in the developing fetus are diploid cells containing a combination of genetic material from both the mother and the father. In other words, sperm cells are haploid (containing half the usual number of chromosomes) and are involved in fertilization, while fetal cells are diploid and contribute to the development of the individual.