BRYOPHYTES DIVISION BRYOPHYTA MOSSES No vascular tissue About

BRYOPHYTES

DIVISION BRYOPHYTA (MOSSES) No vascular tissue About 10, 000 living species Grow in damp places Simple system for moving water within the plant.

Moss plants are short because osmosis will not allow water to travel quickly over long distances

DIVISION BRYOPHYTA CONTINUED Water moves from moss cell to moss cell by osmosis Osmosis - diffusion of water from an area of high concentration to an area of low concentration. This works because mosses are rarely more than a few cells thick. Mosses do not have roots, they are anchored by slender projections called “rhizoids”

Many mosses have primitive conducting cells: Hydroids - water conducting cells Leptoids - sap conducting cells It is unclear whether hydroids and leptoids are homologous or analogous to the xylem and phloem of vascular plants

Peat mosses Sphagnum It grows in dense populations that form peatlands, a wetland habitat that occupies 1% of the earth's surface. Hydrological significance: it can hold up to 20 times its weight in water- commercially useful material in horticulture

How does the sperm get from the male plant to the egg in the female plant?

Bryophytes reproduce using sex cells called spores When a spore reaches the wet ground it will begin to grow into a new plant.

MOSS LIFE CYCLE Alternates between a haploid gametophyte (n) and diploid sporophyte (2 n) phase. The gametophyte is the larger more obvious and longer-lived generation of mosses. The gametophyte produces eggs and sperm

DIVISION HEPATOPHYTA (LIVERWORTS) About In 6, 500 living species Medieval times people believed that plants shaped like internal organs would help heal those same internal organs

Two growth forms - thallose and leafy Liverwort leaf cells each containing two to five (grey) oil bodies (as well as numerous chloroplasts). Absorb water and nutrients through entire surface Form single celled rhizoids for attachment Lack stomata, but contain air pores that remain open "Basal" group of plants, probably most like plant ancestors

A gemma (plural gemmae) is a single cell, or a mass of cells, that detaches from the parent and develops into a new individual. This type of asexual reproduction is referred to as fragmentation. It is a means of asexual propagation in plants.

Gemma Cups

DIVISION ANTHOCEROPHYTA (HORNWORTS) About 100 living species As in other bryophytes, the sporophyte remains attached to its parent gametophyte throughout its life, but unlike these other plants, the sporophyte continues to grow throughout its life; Form symbiotic associations with cyanobacteria

Form symbiotic associations with cyanobacteria, this can give them a bluish color Single chloroplast per cell (important taxonomic character) Spores Have have pseudo-elaters well-defined stomata HORNWORTS: PHYLUM ANTHOCEROPHYTA

WHAT IS A PSEUDO-ELATER? An elater is a cell (or structure attached to a cell) that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. Elaters come in a variety of forms, but are always associated with plant spores. In plants that do not have seeds, they function in dispersing the spores to a new location.

HORNWORT YOUNG

HORNWORT OLD

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