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Like all land plants (embryophytes), bryophytes have life cycles with alternation of generations. [11] In each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cells contain two sets of paired chromosomes. Gametophytes produce haploid sperm and eggs ...
Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be unicellular or multicellular. [1]
Chloroplasts (green discs) and accumulated starch granules in cells of Bryum capillare. Botanically, mosses are non-vascular plants in the land plant division Bryophyta. They are usually small (a few centimeters tall) herbaceous (non-woody) plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide and sunlight to create food by photosynthesis.
Bryophytes, an informal group that taxonomists now treat as three separate land-plant divisions, namely: Bryophyta (mosses), Marchantiophyta (liverworts), and Anthocerotophyta (hornworts). In all bryophytes, the primary plants are the haploid gametophytes , with the only diploid portion being the attached sporophyte, consisting of a stalk and ...
[19] [20] In most species, there is a single cell inside the spore, and a slender extension of this cell called the germ tube germinates from the proximal side of the spore. [21] The tip of the germ tube divides to form an octant (solid geometry) of cells, and the first rhizoid grows as an extension of the original germ cell.
Guard cell – one of the paired epidermal cells that control the opening and closing of a stoma in plant tissue. Heartwood – the older, nonliving central wood of a tree or woody plant, usually darker and harder than the younger sapwood. Also called duramen. Herbaceous – non-woody and dying to the ground at the end of the growing season.
The streptophyte algae (i.e. excluding the land plants) have around 122 genera; they adapted to fresh water very early in their evolutionary history and have not spread back into marine environments. [28] [29] [30] Some time during the Ordovician, streptophytes invaded the land and began the evolution of the embryophyte land plants. [31]
Plant cells differentiate into multiple cell types, forming tissues such as the vascular tissue with specialized xylem and phloem of leaf veins and stems, and organs with different physiological functions such as roots to absorb water and minerals, stems for support and to transport water and synthesized molecules, leaves for photosynthesis ...