A sex organ. One of the major distinctions between land plants and the ancestral green algal protists is that a. Only algal protists have flagellated, swimming sperm and land plants do not. Embryos are not retained within parental tissues of unicellular protista. Meiosis proceeds at a faster pace in algae than in land plants.
Sperms have flagella.
Gametophytes arise from a protonema. Fern e. Seed plant 10. Hidden Seed plants - Angiophyta 11. The cells that attach filamentous algae to a rock or other substrate is like a primitive root. The chlorophytes and land plants are both mostly multicellular.