Biology Chapter 29: Plant Diversity 1

1.2 BYA

cyanobacteria and protists on land

500 mya

colonization of land by plants, animals, fungi

charophytes

green algae, closest relatives of plants

shared traits between charophytes and plants

rings of cellulose, flagellated sperm, phragmoplast

phragmoplast

scaffold for cell plate assembly

embryophytes

plants with embryos

Derived traits of plants

1. alternation of generations

2. multicellular, dependent embryos

3. walled spores in sporangia

4. multicellular gametangia

5. apical meristems

Alternation of generations

the alternation between the haploid gametophyte and the diploid sporophyte in a plant's life cycle

gametophytes produce ____________ by ____________ which fuse and develop into __________

haploid gametes; mitosis; diploid sporophyte

sporophytes produce __________ by _________ that develop into _____________

haploid; meiosis; gametophytes

embryo

diploid, grows into sporophyte, dependent on nutrients from parents, retained in tissue of female gametophyte

sporocytes

diploid cells that undergo meiosis to generate haploid spores

sporopollenin

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

gametangia produce ___________

gametes

male gametangia

antheridia, produce and release sperm

female gametangia

archegonia, produce a single nonmotile egg fertilized in the archegonium

apical meristems

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

470 mya

plants colonize land

bryophytes

nonvascular plants

vascular tissue in plants

Made up of xylem and phloem, it transports fluid and nutrients internally

seedless vascular plants include

lycophytes, manilophytes

lycophytes

club mosses, spike mosses, quillworts

monilophytes

ferns, horsetails, whisk ferns, relatives, most widespread of seedless vascular plants

gymnosperm

group of seed plants that bear their seeds directly on the scales of cones, "naked seed"

angiosperm

A flowering plant which forms seeds inside a protective chamber called an ovary.

bryophytes include

liverworts (Hepatophyta), mosses (Bryophyta), hornwarts (Anthocerophyta)

Dominant generation in bryophytes

gametophyte

Bryophyte gametophytes

a spore germinates into a gametophyte composed of a protonema, 1+ gamete producing gametophores, and rhizoids, flagellated sperm produced in antheridia and egg in archegonium, water required for fertilization

protonema

A mass of green, branched, one-cell-thick filaments produced by germinating moss spores.

gametophores

In bryophytes, a fertile stalk that bears gametangia

Bryophyte Sporophytes

grow out of archegonia, and are the smallest and simplest sporophytes of all extant plant groups, consist of a foot, seta, and sporangium which discharges spores through a peristome

bryophyte sporophytes picture

ecological importance of moss

reduce nitrogen loss from soil

Seedless vascular plants appear

425 mya

dominant stage in seedless vascular plants

sporophyte

xylem

transports water and minerals, includes tube shaped cells called tracheids, flow upwards, dead at maturity, cells strengthened by lignin

phloem

transport food, flows up and down

roots

Absorbs water and minerals from the ground. Anchors plant in ground.

leaves

The main photosynthetic organs of vascular plants.

microphylls

leaves with a single vein

megaphylls

leaves with a highly branched vascular system

sporophylls

modified leaves that bear sporangia

sori

clusters of sporangia on underside of sporophylls

strobili

cone like structures formed from groups of sporophylls

Most seedless vascular plants are

homosporous, producing one type of spore that develops into a bisexual gametophyte

Heterospores produce

megaspores (female gphyte) and microspores (male gphyte)

-phyll

leaf or leaflike