Final answer:
Sporozoans have a life cycle that involves both sporogony and gamogony stages. They do not spend the majority of their life cycle in any single stage like just spores or gametes, and none of the provided options accurately describe their entire life cycle.
Step-by-step explanation:
Sporozoans are part of the protist group and have a complex life cycle that involves multiple stages, often including both asexual and sexual phases. The life cycle stages of sporozoans typically include sporogony (the asexual reproduction phase leading to the formation of spores), gamogony (which involves the formation of gametes), and merogony (asexual reproduction by multiple fissions). However, in the context of the options provided in the question, sporozoans do not spend most of their life cycle as spores, cysts, trophozoites, or exclusively as gametes.
The most relevant stages are not explicitly included as options but to address the question directly, most sporozoans spend the majority of their life cycle in a state that includes both sporogony and gamogony stages, involving the production and development of both sporozoites (infective asexual stages) and gametes (sexual stage). This complexity means that none of the provided options perfectly describes the life cycle of sporozoans.
Protists, including sporozoans, exhibit different life cycles, including haploid and diploid stages, with some having multicellular stages, as seen in the comparison with plants. For example, in the life cycle of malaria-causing Plasmodium (a sporozoan genus), there are multiple stages that include sporozoites, which infect the liver cells, and gametes, which are produced in the blood and taken up by mosquitoes.