Final answer:
Nematodes can be either monoecious or dioecious, depending on the species.
Step-by-step explanation:
Nematodes employ a variety of sexual reproductive strategies depending on the species. Some nematodes are monoecious, meaning they have both male and female reproductive organs in the same individual. Others are dioecious, meaning there are separate male and female individuals.
Caenorhabditis elegans, a commonly studied nematode, is mostly monoecious with self-fertilizing hermaphrodites and some males.