Final answer:
In the haplodiploid system of sex determination, typical in many insects, females arise from fertilized eggs and have a diploid number of chromosomes, while males develop from unfertilized eggs and are haploid, having only a single set of chromosomes.
Step-by-step explanation:
Sex determination in insects with haplodiploid sex determination is a unique system where females are diploid and males are haploid. In this system, unfertilized eggs, which contain only the maternal set of chromosomes, develop into males. Conversely, the fertilized eggs that receive both maternal and paternal chromosomes become females. This is in contrast to the mammalian XY system where the presence of a Y chromosome determines maleness, and the XX combination results in a female. In the haplodiploid system, males have half the number of chromosomes compared to females, which is why males are considered haploid and females diploid.