29 - Seedless Plants

Embryophytes

plants with embryos; true land plants with traits like sporangia, gametangia, apical, meristems, and alternation of generations

alternation of generation

a plant life cycle with two multicellular stages: a haploid gametophyte and a diploid sporophyte

sporophyte

the diploid (2n) stage in the plant life cycle that produces spores via meiosis

placental transfer cells

specialized cells that transfer nutrients from the gametophyte to the dependent embryo

sporangia

structure on the sporophyte where meiosis occurs to produce haploid spores

Sporopollenin

a tough polymer that protects plant spores and pollen from drying out

Gametangia

multicellular organs that produce gametes; including archegonia (egg) and antheridia (sperm)

Archegonia

Female gametangia that produce a single non-motile egg cell

Antheridia

male gametangia that produce flagellated motile sperm

apical meristems

regions of miotic cell division at plant tips that enable longitudinal growth

cuticle

a waxy coating on plant surfaces that helps reduce water loss

stomata

pores in the epidermis of plants that allow for gas exchange

nonvascular plants (bryophytes)

plants without vascular tissue, including liverworts, mosses, and hornworts; gametophyte-dominant

Protonema

a filamentous structure in mosses that develops into the gametophyte

Rhizoids

Root-like structures that anchor bryophyte gametophytes to a substrate

Homospory

production of one type of spore that typically develops into a unisexual gametophyte

brood bodies

small plantlets used for asexual reproduction in mosses

gemmae

balls of tissue in gemmae cups that detach and grow into new plants

bryophyte sporophyte anatomy

includes the foot (anchors to gametophyte), seta (stalk), and capsule (sporangium) with a peristome for spore release