BIO151 UNIT 4 CH. 29 SEEDLESS PLANTS

sporopollenin

a layer of durable polymer; prevents exposed zygotes from drying out

alternation of generations

a type of reproductive cycle that occurs in algae, includes multicellular haploid & multicellular diploid organisms; each multicellular form gives rise to each other

gametophyte

a haploid “gamete-producing plant”; produces haploid egg & sperm via mitosis, which fuse during fertilization, forming diploid zygotes

sporophyte

diploid, zygotes dividing via mitosis produces this, meiosis in these produces haploid spores

spores

reproductive cells that can develop into new haploid organism without fusing into another cell; when divided via mitosis, a new multicellular gametophyte is produced and the alternation of generations begins again

embryophytes

another word for plants

haploid

contains a single set of chromosomes

-primary sex cells (sperm/egg) produced via meiosis

diploid

contains two sets of chromosomes (one from each parent)

-formed by mitosis

gamete

a mature, haploid sex cell

-carries half the genetic material of an organism

fertilization

male gamete fuses with female gamete to form a diploid zygote

zygote

a single diploid cell that results from the fusion of two haploid gametes

bryophytes

nonvascular plants

don’t form a clade (monophyletic group)

includes mosses, liverworts, hornworts

lycophytes

includes club mosses & their relatives

monilophytes

includes ferns & their relatives

seed

an embryo packaged with a supply of nutrients inside a protective coat

gymnosperms

“naked seed” plants since the seeds aren’t enclosed in chambers

angiosperms

consists of all flowering plants

seeds develop inside chambers that originate within flowers

protonema

green, branched, one-cell-thick filaments

has a large surface area that enhances absorption of water & minerals

may produce one or more “buds” which develop into a moss gametophyte

rhizoids

anchor the gametophytes to the ground that lack specialized conducting cells & don’t play a primary role in water & mineral absorption

long, tubular single cells (in liverworts & hornworts)

filaments of cells (in mosses)

gametangia

multicellular structures that produce gametes & are covered by protective tissue

archegonia

a type of gametangia, produces one egg

antheridia

a type of gametangia, produces sperm

foot

embedded into the archegonium, absorbs nutrients from the gametophyte

seta/stalk

conducts the materials to the sporangium

capsule

produces spores via meiosis

peristome

a group of tooth-like structures that open under dry conditions & close when it’s moist

allows moss spores to discharge gradually via periodic gusts of wind that carries them

xylem

conducts most of the water & minerals

tracheids

tube-shaped cells that carry water & minerals up from the roots

phloem

distribute sugars, amino acids, and other products of photosynthesis

megaspores

spores that develop into female gametophytes

microspores

spores that develop into male gametophytes

microphylls

small, spine-shaped leaves that are supported by a single strand of vascular tissue

megaphylls

leaves with a highly branched vascular system

sporophylls

modified leaves that bear sporangia

sori (plural), sorus (singular)

clusters of sporangia, produced by fern sporophylls

strobili

cone-like structures formed by groups of sporophylls

homosporus

a seedless vascular plant that has one type of sporophyll that bears one type of sporangium that produces one type of spore

said spore typically develops into a bisexual gametophyte

heterosporus

has two types of sporophylls, microsporophylls & megasporophylls

what traits of plants are shared with many (or all) algae?

multicellular, eukaryotic, photosynthetic, walls made of cellulose

chloroplasts present in green algae

what are the derived traits which arose in land plants & aren’t shared with algae?

alternation of generations, walled spores, apical meristems

which sex of gamete is motile?

sperm

which type of cell undergoes meiosis during alternation of generations?

diploid sporocyte cells

which types of cell fuse during fertilization?

sperm & egg

sporangia

a specialized sac in fungi, plants, and other organisms

where asexual spores are produced, stored, then released

apical meristems

localized regions of cell division at the tips of roots & shoots

sporocyte

a specialized diploid cell that undergoes meiosis to produce 4 haploid spores

life cycle of bryophytes

an alternation of generations between a dominant haploid gametophyte and a dependent diploid sporophyte

what are the main structures of a bryophyte sporophyte?

consists of a foot, seta (stalk), and capsule

what environmental conditions are required for fertilization in bryophytes

moist, damp environment

what traits separate vascular plants from the bryophyte grade? what are advantages to these traits?

vascular plants have lignified tissue (xylem & phloem), specialized roots, & have a dominant sporophyte life stage

advantages include growing large, transporting water & nutrients efficiently, and higher reproductive success

life cycle of monilophytes (ferns)

a diploid sporophyte is the dominant, vascular, & independent generation. it produces haploid spores via meiosis within the sori

the spores germinate into small, haploid gametophytes (prothallus) that produce swimming sperm & eggs, requiring water for fertilization