Land plant groups

Mosses

worts

ferns

seedplants

Plant timeline

1. Cyanobacteria

2. green algae

3. fern/vascular plants

4. seed plants

Phylogeny

charophytes to land plants

bryophytes to worts/mosses

euphyllophytes to seed plants/ferns

Charophytes

Most closely related to land plants

Land adaptations

Sprorphollenin

stomata

cuticle

secondary compounds

Benefits of moving on land

Unfiltered sunlight

higher CO2

fewer herbivores and pathogens

nutrient rich soils

Challenges of moving onto land

Scarcity of water

Lack of structural support

4 traits of land plants

Alternation of generations (multicellular, dependent embryos)

walled spores in sporangia

Multicellular gametangia

apical meristems/linear growth from root and shoot tips

Cuticle

Waxy coating on leaf to prevent dessication

Secondary compounds

Metabolites used for defense

Non-vascular plant traits

No circulation (nutrient or water) smooth leaaves

small

Non-vascular plant froups

Liverworts, hornworts, mosses, bryophytes,

Vacular plants

Veiny

larger

seedless and seed-bearing

Gametophyte

1n

produce gametes by mitosis

Sporophytes

2n multicellular

formed by gamete fusion

produced haploid spores by meiosis in sporangia

Spore production

Sporophyte

sporocytes (2n mother spores) undergo meiosis in sporangia

produce 4 haploid spores

Gamete production

Gametophyte

SPores fivide in mitosis into gametes

gametes fuse into diploid zygotes

Embryophytes

Embryo stays attached to female gaemtophyte

nutrients transferred from parent via placental transfer cells

Gametangia

Produvr gametes

Archagonia

Female gametangia

egg production

fertilization site

Antheridia

Male gametangia

sperm production/release

bryophyte reproduction

dominant gametophyte generation

sporophytes grow out of archegonia

simplest sporophyte

Bryophyte/sprophyte structures

Foot

seta/stalk

sporangium/capsule

stomata in hornworts and moss

sporphyte

bryophyte sporangium/capsule discharge

From peristome

Peat

Partially decayed plant matter found in bogs

Hornworts

Nonvascular

phylum anthocerophyta

long sledner sporophytes (horns)

Seedless land plants

Vascular

larger

flagellated sperm (need wet environment)

dominant sporophyte generation

lycophytes

pterophytes/monilophytes

5 traits of seedplants

reduced gametophyte

heterosporous

ovules

pollen

seed

fern gametophytes

hermaphroditic

free living

Vascularity

Fluid/nutrient transport

Xylem

Conducts most of the water and minerals and includes dead cells called tracheids

strengthen by ligin

Phloem

Consists of living cells and distributes sugars, amino acids, and other organic products

Lignin

Makes cell walls rigid

aids water-conducting cells

Roots

Anchor

absorbs water and nutrients from the soil

Leaves

Increase surface area capturing more solar energy used for photosynthesis

Microphylls

Leaves with a single vein from sporangia

Megaphylls

Leaves with a highly branched vascular systrm

webbing between veins

True roots

Tap and tuberous roots

Tap roots

large vertically growing roots

Tuberous roots

Modified lateral roots for storage

Modified stems

Corm

rhizomes

tuebr

Sporophylls

Modified leaves with sporangia

Sori

Clusters of sporangia

underside of sporphyll

Strobili

Cone-like structures formed from groups of sporophylls

Homospores

Songle spores mature into hermaphroditic gametophyte

most seedless plants

Heterosporous

Sexed spores that give rise to either male or female gametangia

all seed plants

Megaspores

Develop into female gametophytes

Microspores

Developed into male gametophytles

Phylum Lycophyta

Club mosses, spike mosses, and quilworts

Phylum pterophyta or monilophyta

Ferns, horsetails, and whisk ferns

Ferns

Angiosperms

Gymnosperms

seeds with protective coating

reduced gametophytes

dominant sporophyte generation

heterosporous

ovules

pollen producing

Gymnosperm ovules

female structure with egg

Dioecious

Having male nd female reproductive organs in separate plants or animals

Gymnosperm pollen

Male gametophyte

Seedplant gametophyte

Inside spores

spores are inside sporophyte

Megasporangia

2n tissue

produce megaspores that give rise to female gametophytes where haploid megaspore is formed (meiosis)

Microsporangia

2n tissue

produce microspores that give rise to male gametophytes where haploid microspores are formed (meiosis)

Ovule

Megasporangium

megaspore

protective integuments

Protective integuments in gynospores vs angiospores

Gymno: 1

angio: 2

Megaspore gymnosperms

Haploid cell that grows into female gametophyte, including the egg nucleus

Microspore gymnosperms

Develop into male gametophyte/pollen

Pollen gymnosperms

Contains male gametophyte within the tough pollen wall

Gymnosperm fertilization

Pollen released into the air

pollen grain reaches ovule and germinates

pollen tube grows, digesting through megasporangium

pollen tube reaches egg nucleus

discharges sperm nucleus into egg nucleus of female gametophytes

Pollination

Transfer of pollen to the part of a seed plant containing the ovules

Benefits of pollen

Eliminates the need for a film of water

dispersed great distances by air or animals

Benefits of seeds

Whole ovule

sporophyte embryo, along with its food supply

packaged in a protective coat

dormancy until good conditions

transported long distances by wind or animals

Gymnosperm phyla

cycadophyta

ginkgophyta

gnetophyta

vonferphyta

Cycadophyta (cycads)

Cones

Palmlike

few species

Ginkophyta

1 species ginkgo bilboba

pollution tolerant

studied for memory benefits

Gnetophyta (gnetophytes)

3 genera:

1. gnetum

2. welwitschia

3. ephedra

many leaves

Coniferophyta

Largest phylum

year round photosythesis

Angiosperms

Single phylum anthophyta

seed plants

flowers

fruits

Flowers

Sexual reproduction

diverse shapes linked to pollinator

house gametophyte

modified stems with modified leaves

Flowers arranged in

Whorls

Outer whorl

Sepal

2nd whord

Petal

3rd whorl

stamens (androecium)

inner whorl

Gynoecium

consists of one or more carpels

houses gsmetophyte

Carpel

Ovary style stiga

female gametophyte/embryo sac

Where in the carpel is the embryo sac

In ovule in ovary at base of stigma

Embryo division

Daughter nuclei divide to produce 8 haploid nuclei (2 groups of 4)

2 nuclei (1 from each group) migrate towards center

function as polar nuclei- may fuse

What cell becomes the egg

closest to the micropyle (opening on ovule)

2 extra nuclei

synergids

3 non polar cells left

antipodals

no function

later break down

Integument

forms seed coat

embryo sac

7 cells

8 1n nuclei

stamen

male

modified sporophyll

anther

microsporangium

pollen sacs

Complete flower

a flower that has all four modified leaves

sepals, petals, stamens, and carpels

incomplete flower

A flower that lacks one or more of the four modified leaves

Perfect flower

Has both male/female reproductive parts

Monoecious

Male and female flowers on one plant

dioicous

plant/sporophyte produces either male or female gametophyte separate

Selfing plants

Perfect flowers can theoretically self pollinate

Preventing selfing

Gametophytic self incompatibility

heterostyly

sporophytic self incompatability

Gametophytic self incompatability

Proteins prevent pollen tube from growing

Heterostyly

Stamens and carpels are of different lengths

Sporophytic self incompatibility

Prevents self pollination

pollen and stigma recognize each other as being genetically related, and the pollen tube growth is blocked

Angiosperm pollination

Pollen lands on stigma

germinates

tube grows to ovary

tube enters through microphyle

double fertilization occurs

Double fertilization

Pollen tube discharges 2 sperm into gametophyte in ovule

1 sperm fertilizes egg other sperm fuses into the gametophyte call and spurs endosperm production

double fertilization products

sperm+gametophyte=2n

zygote/new sporophyte

sperm+polar nuclei= 3n endosperm

Cotyledons

seed leaves

Hypogeal cotyledons

Stay below ground

do not photosynthesize

often used for storage

Epigeal cotyledons

Grow in germination

push off seed shell

photosynthesizing

above ground

fruit

mature ovary

protect and disperse seeds

Fruit types

simple

dry

fleshy

aggregate

multiple

Dry fruits

achene

legume

samara

nut

fibrous drupes

drupes

enclosed hard endocarp

fleshy exocarp and mesocarp

stone fruits

samaras

small dry seeds

wings

nut

simple dry fruit

seed enclosed in a hard shell

legumes

split carpel

seeds attach to edges

dry at maturity

True berries

Fleshy

thin skin

seeds inside ovary

Aggregrate fruit

Mutiple ovaries from one flower

Multiple fruits

develop from a group of flowers called an inflorescence

fruit dispersal

eaten

carried on coats

cached by herbivores

wind/water

Monocot

1 cotyledon

petals in 3s

parallel veins

scattered vasc tissue

fibrous root

pollen grain w/opening

eudicot

true dicots

2 cotelydon

larger group

netlike veins

rings of vasc tissue

main tap roots

3 openings in pollen

petals in 4-5s

bilateral symmetry

left and right halves that mirror each other

more species

specialty prevents gene flow

radial symmetry

aymmetry about a central acis

less specialized pollination

3 organs of plants

roots

leaves

stems

root function

anchorage

absorption of water and minerals storage

types of roots

taproot

adventitious roots

fibrous root

taproots

1 vertical root

small lateral roots

water uptake occurs in

root hairs due to more surface area

adventitious roots

arise from stems/leaves

above ground

grow out and down from stems

fibrous roots

no main root

thin lateral roots

monocots and seedless vascular plants

modified roots

propelling roots

strangling roots

pneumatophores

buttress roots

storage roots

haustorial roots

climbing root

Propelling roots

aerial roots

support

strangling roots

grow around objects supporting the plant

epiphytes

pneumatophores

roots grow up into air

for O2 exchange in watery environments O2 from atmosphere

Buttress roots

wedges

support

Storage roots

Storage

tap and lateral roots

Haustorial roots

parasitic

steal water and nutrients from plant hemiparasitic or holoparasitic

Hemiparasititc

Perform photosynthesis

steal water and nutrients

Holoparasitic

Do not photosynthesize

steal sugars from host

climbing roots

adventitous

support climbing plants

negatively phototropiv (ivy likes dark)

stems

nodes

internodes

axillary, apical buds

Nodes of stem

the points at which leaves are attached

Internodes of stem

The stem segments between nodes

Axillary buds

Can form a lateral shoot or branch

Apical bud

Near shoot tip

elongation of young shoot

Apical dominance

Growth concentrated at the tip of a plant shoot

apical bud partially inhibits axillary bud growth

Modified stems

Corm

Rhizome

Stolon

Bulbs

Corm stems

short

underground

storage

Rhizome stems

A horizontal underground stem

produces new shoots and roots

Stolon stems

Ground level/ barely below

horizontal

adventitious roots

produces clone at the end of the stem

Bulb stems

Underground stems

modified leaves included

Leaves

The main photosynthetic organs of vascilar plants

blade=leafs

petiole=joins leaf to a node of the stem

Leaf types

Simple

compound

double compound

Simple leaves

1 petiole to continuous structre

Compound leaves

1 petiole multiple leaflets

double compound leaf

each leaflet is divided into smaller leaflets

Modified leaves

Bracts

tendrils

spines

thorns

storage

bracts

Reproductive structures

attracts pollinators

colorful leaves (poinsettia)

Tendrils

Climbing/attachments

thigmotropic-grows to touch

spines

defense

Storage leaves

Store water/nutrients

succulents

Plant tissues

dermal

vascular

ground

Dermal structures

epidermis (non-woody plants)

cuticle

periderm

trichomes

Periderm

Woody plants

protection

replaces old epidermis

Trichomes

Outgrowths

from shoots

hairlike

insect defense-keeps bugs away from flesh

Vascular

long distance transport between roots and shoots

xylem and phloem

Stele

Vascular tissue of a stem or root in vascular bundles

Vascular cylinder in angiosperms

Ground Tissue

Not dermal or vascular

photosynthesis, metabolism, storage, and support

parenchyma

Collenchyma

Sclerenechyma

Pith

Ground tissue internal to the vascular tissue

Cortex

Ground tissue external to the vascular tissue

Plant cell types

Parenchyma

Collenchyma

Sclerenchyma

Water-conducting cells

Sugar-conducting cells

Parenchyma

Thin-walled

living

photosynthesis and storage

large central vacuole

no secondary cell walls

least specialized

differentiate throughout life cycle

Collenchyma

Strong, uneven, flexible cell wall

living

support

no secondary cell walls-don't restrict growth

Sclerenchyma

Thick, rigid secondary cell wall

dead at maturity

sclereids and fibers

Sclereids

Short and irregular shaped

Have thick lignified secondary walls

nuts/seeds

Fibers of Sclerenchyma

Long skinny threads

Xylem

Tracheids

vessel elements

Phloem

Sieve tube elements

sieve plate

Vessel elements

short thick water conducting

dead at maturity

aligned end to form vessels

end walls have perforation plates

Tracheids

Water transfer and supportive long, thin dead cells

hardened with lignin

Sieve tube elements

alive at functional maturity

lack organelles/nucleus and enzymes

controlled by companion cells

sugar transport

Sieve plates

Between the cells of the phloem where many gaps that allow the phloem to flow through

Companion cells

SPecialized parenchyma cell

nucleus and ribosome serves both cells

perform metabolic functions for sieve tube

Cell growth

Indetermiate growth

determinate growth

annuals

biennials

perennials

Indetermiate growth

A plant can grow throughout its life

determinate growth

stop growing after reaching a certain size

Annuals

1 years life cycle

Biennials

require two growing seasons

Perennials

Multiple growing seasons

Where does growth occur

Meristematic tissue

Meristems

Perpetually embryonic tissue

allow for indeterminate growth

Apical meristems

Root and shoot tips

primary growth

Lateral meristems

Thickens roots and shoots of woody plants

secondary growth

vascular cambium

cork cambium