Bio Plants Unit

Spermatophytes

Seed plants

Sister Clade to horsetails and ferns

Spermatophyte growth

Secondary and primary at Apical Meristems

Spermatophyte secondary meristems

Vascular Cadmium and cork cadmium

Vascular cambium and cork cambium

Vascular cambium makes secondary xylem (wood) and secondary phloem (inner bark)

Cork cambium makes waxy protective cells that become outer bark

Tree rings

Show age and Temperature and Precipitation have marked effect.

Can be used to predict historical things like tennis khan having favorable weather

Monilophytes

Ferns and horsetails

Sister clade to Spermatophytes

Gymnosperms

Clade of seed plants

Woody, and lack protective ovary outside seeds

No flowers or fruits

Only have tracheids so don’t make hard wood (softwood)

Cycads

Subtropical

Short woody trunks; leaves like palm cuz of conv. Evo. Of “pinnate” leaf structure

Many hunted to extinction

Cycads reproduction

Dioecious cones: Females with special seed bearing megasporophyll, males have pollen bearing microsporophyll

Sperm have flagella

Ginkgo

1 relic species

Motile sperm

Dioecious

May live >1000 years

Cultivated in china

Gnetoohytes

Was once thought to be sister to angiosperms cuz of fleshy cones and morphology

Ghetum

Trop. Evergreen trees shrubs and lianas

Can be dioecious or monoecious

Welwitschia

Dioecious

One relic species in naming desert of sw Africa

Insect pollinated

conifers

Outside tropics

Resins (prot. Chemicals)

Well branches and simple leaves

Conifers reproduction

Wind pollinated; seed dispersed by wind birds and mammals

Cones have megastrobilus and microstrobilus

Gametes have no flagella

Megastrobilus

Conifer seeds protected by woody scales

Ovulate cones

Microstrobilus

Conifer pollen bearing herbaceous scales

Microsporangiate cones

Megaspore mother cycle

Meiosis+mitosis makes 4 megaspore but 3 aborted

Develops into megagametophyte w/ megasporangium

Makes pollen chamber for fert.

Archegonia developed w/ hella megagametophyte

Becomes mature ovule

Microspore mother cell maturation

Meiosis 1 and 2 of mother cell make 4 microspores

Tetras of 4 haploid pollen cells

Maturation of these microspores make microgametophytes (pollen)

Fert.

Pollen enters archegonia w/ eggs

Makes zygote

Disintegrates archegonium and creates embryo

Uses megagametophyte as nutritive tissue

Becomes mature seed

Seed

Has 2n embryo

Nutritive tissue (n)

and Seed coat (2n) protective outer layer from sporophyte tissue

Photosynthate

Product of P.S

Source

Where photosynthate is made

Sink

Where photosynthate is being transported to

Source to sink

Sucrose active trans into sieve tube

Brings water from xylem thru osmo.

Pushes contents to sink w/ pressu.

Synthate unloaded and water back 2 xylem

Apoplastic path

Leave metoprolol cells into apoplast before sieve tube and selectively choose which to transport

Symplastic

Stays in simplest and doesn’t do selective trans

Turgor

Cell pressure from water

Turgid

Cells have turgor and cell wall makes it tall and rigid.

When dehydrated they wilt

Xylem pressure

Down when stoma open up when stoma closed

Water up xylem

Water leaves stoma

Pressure difference brings water from xylem

Tension and cohesion created brings up rest of water

Stoma opening

In light H+ leaves bringing in K+ and Cl- bringing in water

Tension increases and guard cell open

Opp. In absence of light

Open during day close at night

Tracheid

Water conducting elements in land plants w/out xylem and phloem

Developed into xylem phloem later

Allowed plant to grow toward light and have better spore dispersal

Rhyniophytes

No roots and anchored through rhizomes which absorbed water thru unicellular filaments rhizoids

Had aerial branches sporangia at leaves and dichotomous branching (2 equivalent branches at apex)

Lycophytes

Club misses and spike misses and quillworts

Sister group to other vasc. Plants

True roots

Dichotomous branching

Simpler vasc. Tiss. In stems than other

Microphylls (simple leaflike structures on stem arranged spirally)

Apical cell division

Sporangia in conelike strobilli (spore bearing microphylls at end of stem)

Vasc. Plant. Sporophyte

Branching independent sporophyte

Produces more spores and has complex development

Sporophyte is large obvious part of plant

Monilophytes

Not dichotomous branching

Reduced true leaves in circles around stem

True roots w/ irregular branching

Large sporophyte small gametophyte ind of eachother

Small short lives gametophyte

Sori (undersurface of leaves w/ sporangia)

Microphylls

Likely first leaflike structures to evolve in vasc plants

Euphyllophytes

Clade of Monilophytes and seed plants

Overtopping (growth pattern where one branch differentiates from and grows beyond others

Megaphyll (larger more complex leaf)

Developed photosynthetic tissue between members of overtop branches w/ greater S.A of branches

Male gametophyte

Heterospory

Microgametophyte

Sperm

Fertilization

Zygote

Embryo

Sporophyte

Microsporangium

Spore mother cell

Meiosis

Microsperm

Microgametophyte

Megagametophyte hetero

Heterospory

Megagametophyte

Egg

Fert

Zygote

Embryo

Sporophyte

Megasporangium

Spore mother cell

Meiosis

Megaspore

Megagametophyte

Homospory

Gametophyte

Archegonium (male) and antheridium (female)

Sperm (male) egg (female)

Fert

Zygote

Embryo

Sporophyte

Sporangium

Spore mother cell

Meiosis

Spore

Gametophyte

Hetero Microgametophyte

Sperm

Fert

Zygote

Embryo

Sporophyte

Microsporangium

Spore mother cell

Meiosis

Microspore

Microgametophyte

Heterospory

Allows for prod. Of many small microspores w/ easy transportation

Large megastores for nutrition and protection of embryo

Allows for long distance fert

Angiosperm

Seed plants w/ reproductive organs in flowers and seeds enclosed in fruits

Vascular plant

Clade sister to gymnosperms

Angiosperm synapomorphy

Xylem has vessels in addition to tracheids

Net venation in leaves

Flowers and fruits

Ovules and seeds enclosed in carpel

Germination of pollen on a stigma

Double fert

Nutritive tissue called endosperm

Flowers

A shoot with modified leaves

Some have sporangia

Sepals or calyx (leaves at base for prot. And attraction)

Petals or corolla for protection and attraction

Stamens (has male microsporangia)

Ovules and seeds enclosed by leaf called carpel

Pistil is fused carpel containing ovary

Style and stigma are in pistil and receive and transmit pollen to ovary

Pollination

Movement of pollen from anther to stigma

Angiosperm life cycle

Male and female separation and development

Double fertilization creates 2n zygote and 3n endosperm

Cotyledons around embryo

Seedling

Repeat

Antipodal and synergids

Accumulations of 6 cells

3 cells in the back of mature ovule is antipodal cells

3 at the opening of the cell is synergids

Pollen development

Each anther sac is microsporangium

2n mother cell undergoes meiosis 1 and 2 to make 4 microspores

Each goes thru mitosis. Making 2 cell pollen grain

One cell is a generative cell dividing by mitosis to make 2 sperm cells

Other is tube cell creating the pollen tube

Tube cell grows a pollen tube to reach ovule when it lands on a stigma

After double fert. Maturation of seed

Zygote becomes embryo w/ 1 or 2 cotyledons (seed leaves)

Cotyledons absorb endosperm or become photosynthetic when seed germinates

3 genetically diff. Individuals in angiosperm seeds

Embryo (2n)

Endosperm (3n) (2 polar nuclei and sperm)

Seed coat (2n) protective outer layer derived from diploid sporophyte tissue of previous generation

Monoecious

Mega and microsporangia in same plant

Dioecious

Mega and microsporangia in different plants

Selfing costs

Inbreeding depression (reduction in fitness because of unmasking of deleterious recessive mutations)

No genetic diversity

Mechanism to prevent selfing

Half of flower plants are genetically incapable of self fert. Because of S-locus proteins

Heterostyly also by producing Pin or thrum flowers w/ different length pistols and stamens

Benefits of selfing

Pass on advantageous traits

Can assure reproduction in a place with low pollinators or mates

Common in invasive plants

Chasmogamous (open) flowers

Flagrant to promote outside fertilization

Cleistogamous (closed) flowers

Small bud like flowers that are not open and are self compatible to produce later in season

Promotion of outcrossing

Mutualistic evolution for other animals to disperse pollen

Different flower structure is for different pollinations

Bee pollination

Blue purple or yellow

Radial or bilateral symmetry

Broad tube with nectar guides

Fly pollination

Pale flower with musky odor

Colored and strongly scented like decaying flesh

Moth pollination

Bloom in evening with pale color and rich fragrance

Hummingbird pollination

Bright colors

Shade of red

Tubular with hella nectar

No smell

Wind pollination

Scent less nectar less inconspicuous flowers

A lot of small dry lightweight pollen

Exposed feathery stigmas and protruding stamens

Causes allergies

Fruit

Mature ovary containing seeds

Berry

Single carpel or multiple fused carpels

Aggregate fruit

Multiple pistols and carpels fused or unfused (strawberries)

Multiple fruit

Fused mass of many individual flowers (pineapple)

Animal dispersal

Promote eaten by animal to be moved in they poop

Bird catcher tree sticks seeds on birds that land on it