What structure produces male gametes in mosses, ferns, and certain algae and fungi?

The structure that produces male gametes in mosses, ferns, and certain algae and fungi is the antheridium. Antheridia are specialized reproductive organs found in these groups of plants and organisms, serving specifically to generate sperm cells. In the life cycles of mosses and ferns, antheridia are typically located on gametophytes, which are the haploid phase that produces gametes through mitosis.

This specialized structure plays a crucial role in sexual reproduction, allowing for the fertilization of female gametes produced in the archegonia, another type of reproductive structure. Understanding the function of antheridia helps clarify the reproductive strategies of non-vascular plants and some lower vascular plants, highlighting the diversity of reproductive adaptations in the plant kingdom.