Chapter 25-26: Overview of Green Plants

Archaeplastida

what supergroup are green plants in?

viridiplantae

what kingdom are the green plants in?

chlorophytes, charophytes, and land plants

what types of green plants are in the Archaeplastida supergroup?

a species of freshwater green algae

what was the common ancestor of all green algae and land plants a little over 1 BYA?

chloroplasts, chlorophylls a and b, carotenoids, cellulose in cell walls, and store carbohydrates as starch

what are the 4 key characteristics of plants?

false 

T/F: all photoautotrophs are plants 

haplodiplontic

what type of life cycle do plants have that involves the alternation of life cycles?

gametophyte

haploid; produces haploid gametes

sporophyte

diploid; produces haploid spores

chlorophytes 

early green algae 

chloroplasts similar to land plants, microscopic, 2 anterior flagella, reproduce sexually and asexually, and unicellular

what are the characteristics of chlorophytes?

no

are chlorophytes haplodiplontic?

volvox and ulva

what are two examples of chlorophytes?

volvox

colonial chlorophyte made of a hollow sphere with s single layers of cell, each having 2 flagella

ulva

sea lettuce; multicellular chlorophyte that has a haplodiplontic lifestyle

same appearance

what is the appearance between the ulva gametophyte and sporophyte? 

charophytes

sister clade to land plants

300

how many species of charales are there?

macroscopic and plant-like plasmodesmata

characteristics of charophytes

land plants

charophytes are the sister clade to?

nonvascular plants

what does the term bryophytes refer to?

mosses

what does phylum Bryophyta refer to?

require water for sexual reproduction, lack tracheids, and mycorrhizal associations enhance water uptake

characteristics of bryophytes

liverworts, hornworts, and mosses

what are the three clades of bryophytes?

conspicuous and photosynthetic

what is the best way to describe the bryophyte gametophyte? 

small and dependent on the gametophytes

what is the best way describe the bryophyte sporophyte?

hepaticophyta

liverwort phylum

flattened gametophytes with liverlike lobes, form gametangia in umbrella-shaped structures, and can undergo sexual or asexual reproduction

characteristics of liverworts

arche 

female reproductive structure 

anther

male reproductive structure

gemma cup

liverwort asexual reproductive structure

anthocerotophyta

what phylum are hornworts in?

photosynthetic and embedded in gametophyte tissue

what are the characteristics of the hornworts sporophyte? 

true

T/F: the sporophyte is nutritionally dependent on its parent

bryophyta

what phylum are mosses in?

small, leaflike structures around a stemlike axis

how would you describe the gametophyte of mosses?

rhizoids 

what are mosses anchored to substrates by?

rhizoids

thin filaments that anchor the plant to the substrate

gametangia

structure on the gametophyte in which gametes are produced

multicellular gametangia

what forms at the tips of gametophytes in mosses?

archegonia

female gametangia 

antheridia

male gametangia

water

what do moss antheridia need for reproduction?

protonema

tangle of single-celled filaments that forms from the haploid spore

tracheophytes 

vascular plants 

lycophytes, pterophytes, and seed plants

what are the three extant phyla of tracheophytes?

reduced in size relative to the sporophyte

how has the tracheophyte gametophyte and multicellular gametangia changed during evolution?

club mosses

what are some examples of lycophytes?

ferns, whisk ferns, and horsetails

what are some examples of pterophytes?

angiosperms and gymnosperms

what are some examples of seed plants?

ancestral green algae and embryophytes 

what are the common ancestors of all bryophytes and tracheophytes? 

vascular tissues, cuticle and stomata, mycorrhizal associations, and shift to dominant diploid generation

what are the adaptations to terrestrial life that tracheophytes made?

xylem and phloem

what are the vascular tissues?

xylem

conducts water and dissolved minerals upward from the roots

phloem 

conducts sucrose and hormones throughout the plant

cuticle

waxy coating on the outside of the plant to increase water retention

stomata

regulatable pores for getting more CO2 or to reduce evaporation

water retention and mineral nutrients

what benefits do plants get from mycorrhizal associations?

provides a genetic backup plan

why is a dominant diploid generation beneficial against UV radiation? 

dominant in the tropics, lack seeds, superficially resemble mosses, and sporophyte dominant

what are the characteristics of lycophytes?

homosporous

one type of gametophyte that produces both antheridia and archegonia

homosporous and require free water for flagellated sperm

what are the general characteristics of pterophytes?

equisetum 

what is the single genus of horsetails?

ribbed, jointed photosynthetic stems, silica deposits in cells, scale-like leaves at nodes, and stems arise from rhizomes

characteristics of horsetails

deters herbivores from eating the plant

what is the benefit of silica in horsetails?

rhizomes

modified underground stem that grows horizontally to the soil surface and has nodes and internodes

found in tropics, sporophyte has evenly forking green stems without true leaves or roots

characteristics of whisk ferns

ferns

what is the most abundant group of seedless vascular plants?

conspicuous sporophyte and a smaller gametophyte

describe the sporophyte and gametophyte of ferns

increase photosynthetic surface area

what do the leaves on ferns do?

sporophytes have rhizomes and fronds develop as fiddleheads

describe the basics of fern morphology 

greater development, independence, and dominance of fern’s sporophyte

how does the fern life cycle compare to the bryophyte life cycle?

photosynthetic but lacks vascular tissue

describe the fern gametophyte

sori

groups of sporangia on the back of fronds

haploid spores

what do the diploid mother cells in sporangia produce?

snapping or spring-release

what are the two mechanisms for spores to be catapulted?

400 MYA

how many years ago did seeds first appear?

protects and provides food for embryo, allows for survival in harsh conditions, and later development of fruits enhanced dispersal

what are some of the benefits of seeds?

embryo, endosperm, and seed coat

what are the three parts of a seed?

pollen grains, dispersed by air or a pollinator, and don’t need water

what are the characteristics of the male seed gametophytes?

develop within an ovule and enclose within diploid sporophyte tissue in angiosperms

what are the characteristics of female seed gametophytes?

gymnosperms

plants with “naked seeds”

coniferophytes, cycadophytes, gnetophytes, and ginkophytes

what are the four living phyla of gymnosperms?

no flowers or fruits and exposed ovule

what are two defining characteristics of gymnosperms?

coniferophyta

what phylum are conifers in?

pines, spruces, firs, and hemlocks

what are some examples of conifers?

colder and sometimes drier regions

where are conifers usually found?

timber, paper, resin and taxol

what are some important products we get from conifers?

needlelike leaves in clusters, thick cuticles and recessed stomata, and canals with resin

characteristics of pines

deter insect and fungal attacks

what is the benefit to the resin in pines?

upper branches

where are female cones found on pines?

lower branches

where are male cones found on pines?

large, woody scales, two ovules, and produce female gametophytes by meiosis

characteristics of female cones 

small and papery and produce male gametophytes by meiosis

characteristics of male cones

to prevent self-fertilization

why are male cones located lower on the trees?

2 or more

how many seasons does it take female cones to mature?

cycadophyta

what phylum are cycads in?

slow growing, found in tropical or subtropical regions, and the sporophytes resemble palm trees

characteristics of cycads

ginkgophyta

what phylum are ginkgos in?

ginkgo biloba

what is the one living species of ginkgos?