Green algae
Green algae, bryophytes and vascular plants all have chlorophyll a and b, and the chloroplast structures are similar. Like green algae and land plants, bryophytes also produce starch stored in the plastids and contain cellulose in their walls. Distinct adaptations observed in bryophytes have allowed plants to colonize Earth's terrestrial environments. To prevent desiccation of plant tissues in a terrestrial environment, a waxy cuticle covering the soft tissue of the plant may be present, providing protection. In hornworts and mosses, stomata provide gas exchange between the atmosphere and an internal intercellular space system. The development of gametangia provided further protection specifically for gametes, the zygote and the developing sporophyte. The bryophytes and vascular plants (embryophytes) also have embryonic development which is not seen in green algae. While bryophytes have no truly vascularized tissue, they do have organs that are specialized for specific functions, analogous for example to the functions of leaves and stems in vascular land plants.