Which unit of the following life cycle is mobile and self-propelled? Antheridium Archegonium Archegonium Gametophyte Protonema Seta Spermatozoid Spore Sporophyte

The correct answer is **Spermatozoid**.<br /><br />Spermatozoids, also known as sperm cells, are the male gametes in plants like mosses and ferns. They have flagella (whip-like appendages) that enable them to swim through water to reach the female gamete (egg) for fertilization. This motility makes them self-propelled and mobile.<br />