Learn: Bio 29th (seedless vascular plants)

green algae are called what?

charophytes

Zygnematophyceae

the closest living relatives of plants

Plants are not descended from modern charophytes, but

share a common ancestor with them

Charophytes have a coating of _______________________, a polymer that prevents zygotes from drying out

sporopollenin

Sporopollenin is also found in

plant spore walls

what are the benifits of moving from water to land

The move to land provided benefits: unfiltered sunlight, more plentiful CO2, and nutrient-rich soil

Four key traits appear in nearly all plants but are absent in the charophytes?

•Alternation of generations

•Walled spores produced in sporangia

•Apical meristems

alternation of generations

alternation of generations

Type of plant life cycle consisting of multicellular forms that gives rise to each other in turn.

The multicellular haploid gametophyte produces

haploid gametes (sperm and eggs) by mitosis

•The multicellular diploid sporophyte produces

haploid spores by meiosis

Spores develop into gametophytes and fertilized eggs (zygotes)

develop into sporophytes

The diploid embryo

is retained and protected within the tissue of the female gametophyte

Plants are called

embryophytes because of this dependency of the embryo on the parent

•The sporophyte produces spores in multicellular organs called

sporangia

•Spore walls contain ___________________, which makes them resistant to harsh environments

sporopollenin

Localized regions of cell division at the tips of roots and shoots are called

apical meristems

These cells divide continuously, enabling elongation of roots and shoots for better

resource acquisition

stomata

pores that facilitate gas exchange between the outside air and internal plant tissues

cuticle

a waxy covering of the epidermis that reduces water loss

vascular tissue

cells joined into tubes for the transport of water and nutrients

vascular plants

Plants that have a complex vascular tissue system

plants lack an extensive transport system

Nonvascular

bryophytes

All nonvascular plants—liverworts, mosses, and hornworts—are informally called

Seedless vascular plants

Have an extensive vascular transport system, but do not produce seeds

what are the two clades of seedless vascular plants

Lycophytes, Monilophytes

Monilophytes

ferns and their relatives

lycophytes

are club mosses and their relatives

seed

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

Seed plants can be divided into two groups

gymnosperms, angiosperms

Gymnosperms

form a clade that produce seeds that are not enclosed in chambers ("naked seeds")

Angiosperms

form a clade that produce seeds that develop inside chambers that originate within flowers

Bryophytes are represented today by three phyla of small herbaceous (nonwoody) plants

liverworts, mosses, hornworts

liverworts phylym?

hepatphyta

mosses phylum

bryophyta

Hornworts phylum

Anthocerophyta

•Haploid gametophytes are dominant (larger and longer-living than sporophytes) in all ?

bryophytes

•Moss spores produce a mass of green, branched, one-cell-thick filaments called a

protonema

Rhizoids

are root-like structures that anchor gametophytes to the substrate

Vascular tissue allowed plants to _____________

grow much taller

Seedless vascular plants are still restricted to moist habitats where the ____________ can swim to the egg

sperm

Living vascular plants are characterized by

•Life cycles with dominant sporophytes

•Transport in vascular tissues called xylem and phloem

•Well-developed roots and leaves

•Spore-bearing leaves called sporophylls

what are the two types of vascular tissue

xylem and phloem

Xylem

conducts most of the water and minerals and includes tube-shaped cells called tracheids

Xylem cells are dead at functional maturity and are lignified:

strengthened by the polymer lignin

The cells of the __________ tissue are arranged in tubes for transport of organic materials, such as sugar

phloem

_______________ cells are alive at functional maturity

Phloem

Roots

are organs that anchor vascular plants into ground and absorb water and nutrients from the soil

Leaves

increase surface area for light capture and conduct most of the photosynthesis in plants

two types of leaves?

microphylls and megaphylls

Microphylls

small, often spine-shaped leaves with a single vein, are found only in lycophytes

Megaphylls

larger leaves with a highly branched vascular system, are found in all other plant groups

Sporophylls

are modified leaves with sporangia

Sori

are clusters of sporangia on the undersides of fern sporophylls

Many

lycophytes and most gymnosperms have strobili, clumps of sporophylls in cone-like structures

The sporophylls of angiosperms are called?

carpels and stamens

Most seedless vascular plants are ____________?

homosporous

The spores of seedless vascular plants usually produce ______________________________________________________________?

bisexual gametophytes (i.e. hermaphroditic)

All seed plants and some seedless vascular plants are ?

heterosporous

They have two types of sporophylls bearing different sporangia that produce different spore types

Megasporophylls bear _________________________, which produce relatively large megaspores

megasporangia

Megaspores develop into

female gametophytes

Microsporophylls bear microsporangia, which produce relatively small

microspores

•Microspores develop into

male gametophytes

There are two clades of seedless vascular plants

Phylum Lycophyta

Phylum Monilophyta

phylum lycophyta

Includes club mosses, spike mosses, and quillworts.

Phylum Monilophyta

ferns, horsetails, whisk ferns

Fern sporophytes have large megasporophylls (fronds) that are divided into

leaflets

Horsetail sporophytes have jointed stems with rings of _________________________________

small leaves or branches

________________ Gametophytes are bisexual

horsetails

Whisk fern sporophytes have dichotomously branching stems but

no roots

whisk ferns are ?

All are homosporous with bisexual gametophytes