2 Seedless Plants How do seedless plants reproduce? Include all nonvascular plants and some vascular plantsVascular vs. nonvascularNonvascular plants do not have structures that transport substances through the plantSubstances move from cell to cellVascular plants have tube-like cells that transport water & substances throughout the plant
4 Importance of SporesIf you want to grow plants (mosses or ferns) that reproduce by spores, can you buy a packet of seeds?These plants do not reproduce by seedsMosses and ferns contain parts called spore casesSpore cases contain spores; when they break open spores are released – how are they spread?
5 Nonvascular Seedless Plants Mosses are an example of nonvascular plantsSporophyte stage of these plants is small and is easily overlookedMosses are green, low-growing masses of plantsThis is the gametophyte stage (which produces sex cells)
6 Nonvascular Seedless Plants If you were to look closely at the moss, you might see brown stalks growing up from the tip of the plantThis is the Sporophyte stageBrown capsules are on tips of plantsContain millions of sporesWhen conditions are right, capsule opens and spores fall to ground or are carried by windNew mosses can grow from each spore & cycle begins againFigure 6: page 209
7 Nonvascular Plants Nonvascular plants can also reproduce asexually If a piece of moss gametophyte breaks off, it can grow into a new plantLiverworts: form small balls of cells on surface of gametophyte plant; then carried away by water and grow into a new gametophyte plant if they settle in the right environment
8 Vascular Seedless Plants Millions of years ago most plants were vascular seedless plantsMost are ferns but others include horsetails and club mossesAll of these plants have structures to transport water and nutrients in the plantThe gametophyte stage is small and often over-looked
9 Ferns Fern plants seen in nature and houses are fern sporophyte plants Fern leaves are called frondsFronds grow from underground stem called rhizomesRoots that anchor plant also grow from rhizomesFern sporophytes make food by photosynthesis
10 FernsFern spores produced in structures called sori (sorus) usually on underside of frondsSori look like crusty, rust-brown bumpsIf a fern spore lands on damp soil it can grow into a small, green, heart-shaped gametophyte called a prothallusVery hard to see because they are very small (5mm-6mm)Prothallus contains chlorophyll
11 Ferns Ferns can reproduce asexually, also Fern rhizomes grow and form branchesNew fronds and roots develop from each branchThe new rhizome branch can be separated from the main plantIt can then grow on its own and form more fern plants
12 Section 2: Summary Seedless plants reproduce by forming _______. Seedless plants include all nonvascular plants and some vascular plants.Spores are produced by the sporophyte stage and can grow into gametophyte plantsThe sporophyte ________ photosynthesize.Fern sporophytes have green fronds that grow from underground rhizomes.
13 Review Questions Describe the life cycle of mosses. Explain the stages of the life cycle of a fern.Compare and contrast the gametophyte plant of a moss and the gametophyte plant of a fern.Describe asexual reproduction in seedless plants.Why do some seedless plants reproduce only asexually during dry times of the year?