THE EARLY LAND PLANTS BRYOPHYTES

LAND PLANT ADAPTATIONS‣ A cuticle –protective coveringthat preventswater loss

Multicellularreproductiveorgans – to protectthe zygote

Lignin and celluloseproviding support for soft plant tissues

Stomata - allowfor the exchange ofgases.

CHARACTERISTICSof Mosseso Leaf-like structureso Lack of vascular tissues – transportwater by osmosis and diffusiono No true stemso No true roots (rhizoids)o Inability to grow large (3/10 – 8 in.)

MOSSES Resemble a tuft orcarpet Stem-likeprojection withleaf-like clusterssurrounding it Rhizoids anchorplant to soil

LIFE CYCLE OF A MOSSDiploid, sporeproducing stageProduced throughmitosisHaploid, gamete producing stageProducedthroughmeiosis

REPRODUCTION Sperm are contained in theantheridium. Eggs are in the archegonium. Water is necessary for fertilization,as sperm must swim to the eggs. After fertilization, a zygote forms andproduces the slender stalk(sporophyte) that contain sporeswithin a capsule.

IMPORTANCE OF MOSSES “Pioneer” plants; create new soil Forms top soil Prevents erosion Sphagnum moss forms peat; used asfuel

LIVERWORTS Less familiar than moss Grow in wet places (water needed forfertilization) Look like liver-shaped, leathery leaves laidflat on ground; because of their shape,they were thought to have the ability tocure liver disease. Umbrella shaped structures hold male andfemale organs. Reproduce asexually by gemmae; smallcups located on the leaves.

Liverworts w/ gamete producingstructures

HORNWORTS Named for the hornlike appearanceof the sporophyte. There are only about 100 speciesthroughout the world.

POWERPOINT QUIZ Name the three groups of plants inthe division Bryophyta.

2 adaptations of land plants Cuticle Stomata Cellulose & Lignin Pollen transport Multicellular reproductive structure

Life cycle of the Bryophytes iscalled: Alternation of generations