Phloem conduits of living tissue that distribute the products of photosynthesis throughout the plant. That is, roots are different from holdfasts. Like algae they have flagellated sperm. These have well-develop roots and rigid stems. They are largely wet-habitat organism, and have flagellated sperm.
Seeds are important for two reasons.
Do not have flagellated sperm. Direct union of these haploid gametes leads to new diploid indivdual. Plants appear to have inherited the alternation of generations from the multicellular green algae. Review of the alternation of generations in mosses, ferns, gymnosperms and angiosperms. In mosses, the gametophyte is dominant.