Combo with "Plant Evolution" and 4 others
Heteromorphic alternation of generations
"Interpolation theory" · Sporophyte and gametophyte are very different in structure
Label F
"Naked Seeds"
Loss of sporopollenin in zygote, now in spore walls
"heterochrony theory" heterochrony = change in rate or timing of development
Cyanobacteria - Anabeana
"heterocyst" = cell in filamentous anebaena - thicker cell wall (helps exclude oxygen - helps Nitrogen fixation because oxygen competes w/ nitrogen fixation enzyme "nitrogenase") - polar body "akinete" = resistant cells (huge in size) designed to help bacteria survive through severe conditions like desiccation and high temps
Hornwort Life Cycle
(Almost) Co-Dominance Alt of Generations --long sporangium -holds spores (oldest at top) -columella -split tip --pseudo-elaters -multicellular -not hydroscopic -originate from different parent cell than spore --foot -absorbs nutrients from gmt to spt -placental transfer cells -no seta
Rapid evolution late Silurian/Devonian..time a-k
(a) tracheids, (b) dichotomous branching with terminal sporangia, (c) stomata, (d) pseudomonopodial branching (e) microphylls, (f) overtopping, (g) planation, (i) megaphylls, (j) woody growth, (k) seeds
Flower parts
*Carpel* -- Folds inward to protect its reproductive parts -- All parts of female (Ovary, style stigma) *Pistil* -- Many/collection of carpels -- Female segment of flower *Ovule* -- Megagametophyte and egg *Stamen* -- Folds outward/opposite way of carpel to show sporangium/sori (Anther) -- Has anther and filament
Seed rules
*Components of seeds* -- Dormant embryonic sporophyte (New sporophyte) -- Nutritional resource (From megagametophyte) -- Seed coat (From parent sporophyte) -- Seeds are multigenerational -- Produces inside cone or flower -- Resistant to unfavorable condition (passes through digestive tract and fire resistant)
Plant's adaption to life on land
*Cuticle* -- Waxy layer for waterproofing *Pigment* -- Protect from UV radiation -- Utilized light wavelength (depending on chlorophyll) *Gametangia* -- Enclosed and protection for gametes *Embryo* -- Sporophyte generation protected by parent plants -- Provide protection of food/nutrients in seed *Resistant spores* -- Resist decay and desiccation of water (Not drying up) *Vascular tissue* -- Transport materials throughout body of plant (Xylem and phloem) -- Skeletal support -- Have specialized organs (roots, stems, etc) -- Mutualistic association with fungi (mycorrhizae)
Gymnosperms
*Cycads/Cycadophyta* -- Dominant during Jurassic period -- Seen throughout tropics today -- Have male/female cones (Heterosporous and Heteromorpous) *Gnetophyta* *Ephedra* -- Globally distributed -- Exhibit secondary growth -- Alkaloid stimulant and decongestant -- Able to release chemical compounds (Ephedrine, Pseudephedrine) *African Welwitschia* -- Dioecous (Male or female) -- Two leaves grows from base -- Water is collected by leaves due to fog belt along Namibian Coast -- Live up to 400~1500 years *Ginkgos/Ginkophyta* -- Living fossils: Ginkgo Biloba -- Dioecious: Male and female plant as individuals -- Deciduous: Shed leaves during fall (vibrant yellow) *Confers/Conferophyta* -- Dominated Mesozoic forest -- Dominate boreal forest -- Largest, biggest organism, and oldest plants -- Most successful phylum (Oldest species) -- Needle-like leaves -- Use for timber industry -- Seed plants w/o flower
Arrangement of flower plants
*Dioecious* -- Male and female parts on different plants -- Less common type of flower *EX:* Willows, date palms, humans, etc *Monoecious* -- Male and female part on one plant -- Most type of flowers *EX:* Aspen, tomato, etc *Perfect flower* -- Possess both stamen and carpels -- Occur only on monoecious plants *Imperfect flower* -- Posses either stamen or carpel -- Can occur in monoecious or/and dioecious plants *EX:* Corn
Flower
*Generalist* *Pros:* -- Always have variety of species to come and spread your pollens and deliver to other flowers *Cons:* -- High probably of a pollinator not meeting your type of species or does not have your type of pollen (risk of not receiving your type of pollen) *Specialist* *Pros:* -- Monopoly of species (Only have one species to spread pollinate) *Cons:* -- No variety if pollinator dies, thus no pollinator to spread pollens
Pollinator
*Generalist* *Pros:* -- Variety of flowers to get nectar *Cons:* -- Cannot interact with specialized flowers, thus are off limit because some flowers are specific *Specialist* *Pros:* -- Not competing with other species *Cons:* -- No variety if plant dies, thus not able to pollinate other plants and not able to get nectar because flower disappeared
Tracheophyte/Nonseed Tracheophyte life cycle
*Heteromorphic* -- Sporophyte/gametophyte looks different -- Sporophyte larger -- Photosynthetic gametophyte *Homosporous* -- Similar spores -- Produces one type of spores
Megaphyll and Microphyll
*Megaphyll* -- Leaf with more than one vein or vascular trace *Microphyll* --Lleaf with one single, unbranched leaf vein
Monilophytes (Ferns and allies)
*Phylum Sphenophyta (Horse tails* -- Equisetum: Surviving genus -- Grow at base of stem segment (Cell division occur at bottom of stem) *Phylum Psilophyta (Whisk Ferns)* -- Reduced leaves -- Have rhizomes instead of roots -- Surviving Rhyniophyta -- Sister group to ferns -- Molecular data suggested modern origin *Phylum Pterophyta (Ferns)* -- Most fern forms monophyletic lineages -- Roughly ~12,000 species -- Megaphyll leaves well developed -- Sory (Clusters of sporangia) on underside of leaves
Flowers aid reproduction
*Pollination* -- Produces pollen -- Attract pollinator due to colorful -- Receives pollen from another plant -- Pollen tube delivers sperm -- Tube delivery ensure fertilization occur -- Increase viable offspring *Seed dispersal* -- Seed dispersed by wind, water, animal -- Seed mature within ovary -- Fruit = mature ovary -- Variety of fruit types
Rhizomes and Rhizoids
*Rhizome* -- Bundle of stems that is underground and roots form on tracheophyte plants -- Absorbs water and minerals by producing rhizoids *Rhizoid* -- "root-like" structure found on non-vascular plants -- Structure anchors nontracheophytes to their substrates -- Has unicellular hair-like structures grown off the rhizome
History of Tracheophtytes
*Silurian Period* -- First tracheophyte fossil found -- Tracheophyte evolved once in phylogenetic tree *Devonian* -- Tracheophtytes well established -- Forest developed by end of period
Xylem and phloem
*Xylem* -- Conduct and transport water -- Can undergo apoptosis -- Provide support and strength (Cell wall reinforced with lignin) *Lignin* -- Organic molecule -- Resistant to digestion *Phloem* -- Conducts and transport sugar/nutrients -- Living cell -- Evolution history unclear -- Have companion cells to help facilitate
Did the earliest land plants ruin the weather?
- First originated in the "Ordovician" & sucked up a lot of the co2 in the atmosphere via photosynthesis o When co2 levels dropped, temperature fell to an ice age - Even though co2 levels were much higher at this time than they are now, the temp was much lower... why is this? - Back then, the solar output was much lower than it is now
Basal Green Eukaryotes (plants) - Chlorophyceae
- Formation of the phycoplast (how chlorophycaea divide - not furrowing like the ulvophyceae do) o Before the cell starts to divide, it develops microtubules parallel with the plane of cell division - Centripetal pattern of division o Phycoplast = all of the microtubules collectively
Charophyceaean algae synapomorphies (zygnematales, choleochatales, chara)
- Sporopollenin in zygote walls (Found in spore and pollen grain walls and in the zygote walls of these specific organisms were looking at. Sporopollenin is very resistant to degradation) - Rudimentary phragmoplast (Partial phragmoplast (forms microtubules perpendicular to cell division.) Completes process of cell division with furrowing) · Centrifugal
Cyanobacteria
- W/o it there would be no terrestrial life - photosynthetic - monophyletic lineage of photosynthetic prokaryotes (if include plastids) - autotrophs (make own food through photosynthesis)
Cyanobacteria reproduction
- cell division by fission, fragmentation, - no sexual reproduction - no mitosis or meiosis
Zygnemateles - Desmids
- made up of two semi cells - isthmus in middle w/ nucleus - pyrenoids in chloroplasts - vacuoles on each end
Streptophyta Synapomorphies
- open mitosis (nuclear membrane breaks down during mitosis) - multilayered structure in motile cells (associated w/ flagellar roots that anchor the flagella into the cell body) - glycolate oxidase (respiratory enzyme)
Deciduous
-- Ability to shed/lose leaves during certain seasons -- Undergo "hibernation" status
Seeds endurance
-- Able to pass through digestive tract -- Able to endure harsh weathers (dry land, etc) or hazards (fire, snow, etc) -- Able to germinate from underground to get sunlight
Galls
-- Abnormal plant growth -- Wasp causes gall and larvae are born
Phylum Lycophyta (Club Mosses)
-- Ancestral lineages to carboniferous forest -- Few remaining left -- Have microphyll leaves -- Dichotomous branching growth (Splits into two sections) then apical growth occurs -- Have spores on strobili
Describe the plants in Jurassic
-- Angiosperms on the rise (Few flowering plants) -- Cycadophyta were around (Most common gymnosperm during period) -- Conferophyta were big and dominant during Mesozoic -- Ginkgophyta were around too -- Most gymnosperms can be seen
Angiosperm life cycle
-- Are much like gymnosperms -- Are heterosporous (microspores and megaspores) -- Double fertilization occurs (unique to flowering plants) due to two sperm produced -- Have polar nuclei and egg that are fertilized by sperm
Streptophytes --> Charales
-- Develop through branched apical growth -- Have molecular data (DNA/rRNA) -- Have chloroplast structure -- Able to undergo cell division -- Sister group to land plants
How angiosperm exploded in diversity
-- Diversified because symbiotic relationship with insect and herbivores. -- Herbivores were able to eat plants, thus plants were able to make chemicals against herbivores and a chemical warfare began. Meanwhile herbivores evolved to adapt against chemical and competition began between both species of organisms ("arms race" between organisms) -- Insects were pollinating plants and spreading pollen among flowers, thus flowers were able to diversify (Mutualism)
Fertilization
-- Egg and sperm join to create zygote
Angiosperms
-- Flowering plants -- Origin originated from Mesozoic (Probably Jurassic period) -- Explosive radiation in Tertiary -- Ovary responsible for dispersal *Flowers are derived from modified leaves* -- Aid in pollination (attracts pollinators) -- Mature ovary protect seeds -- Great variation in structure/strategy *Coevolution with insects* -- Pollination (Spreadage of pollens from flowers) -- Herbivory (Food for organisms) -- Competition among both organisms allowed explosive evolution to occur in both species
Flower morphology/evolution
-- Flowers are modified dramatically -- Monophyletic group/lineages -- Has carpel, pistil, and stamen
African Wlwitschia (Gtenophyta) collect water?
-- Fog belts; leaves sucks in water due to fog belt and easier at night because fog is thicker and water form easily
Heterosporous life cycle
-- Gametophyte generation dependent on sporophyte *Female event* -- Megagametophyte and egg retained -- Ovule = megagametophyte and egg -- Surrounded by sporophyte tissues *Male event* -- Microgametophyte produes sperms (Pollens) -- Pollen spreads to female plant by wind or pollinators -- Pollen tube delivers sperm to egg -- Water not required
Nonvascular/Nontracheophyte plants
-- Gametophyte generation dominant -- Have tracheid cells (lack vascular tissues) for support and transport -- Grows in moist habitat -- Lack different organs (anchored to substrate by rhizoids) *EX:* Bryophyta, Hepatophyta, Anthocerophyta (Are homosporous: produces one type of spores)
Monoecious
-- Has both male and female on same individual -- More common among plants/flowers
Dioecious
-- Has male or female tree -- Less common among plants/flowers -- Separate identity and individuals, not on same tree
Glaucophytes
-- Have peptidoglycan in chloroplast
Anthocerophyta (Hornworts)
-- Have stomata on leafy gametophyte -- Sporophyte develops from base of plant -- Symbiosis with cyanobacteria -- Are roughly ~20 cm tall
Seed plants
-- Many seed plants exhibit secondary growth -- Have primary and secondary growth -- Grows upward (Primary growth) and laterally (Secondary growth) -- Cell division occurs in meristem tissue -- Allow for lateral growth (increase in girth) -- Produces woods, and plant can reach great height
Hepatophyta (Liverworts)
-- Most ancestral plant group -- Asexual reproduction (Fragmentation, Gemmae cup)
Bryophyta (Mosses)
-- Most successful nontracheophyte (Nonvascular plant) -- Apical sporophyte growth -- Hydroid cells for transport -- Have sphagnum bags
Plants Characteristics (CLASS NOTES)
-- Multicellular photoautotroph -- Have chlorophyll a/b -- Receive chloroplast through primary endosymbiosis -- Receive starch for sugar storage -- Have cell wall of cellulose (Polysaccharide) -- Are heteromorphic alternation of generation -- Embryonic sporophyte protected by parent tissues
Nonvascular/Nontracheophyte plants growth in moist habitat
-- No great cuticle for protection -- Need to access water -- Require water for fertilization -- Water conservation is limited
Pollination
-- Process of microgametophyte (pollens) traveling to another plant through a symbiotic relationship with other organisms or pollinator, or through some other way
Seed plants (Gymnospermae)
-- Seed plants are heterosporous *Heterosporous* -- Produces different spores -- Meiosis occurs in two way (Megasporangium/Microsporangium) *Heteromorpous* -- Different shape and form or looks *EX:*Megasporangium and mircosporangium looks different
Rhodophyta (Red Algae)
-- Shares ancestor with green algae -- Lack mobile cells (No flagella) -- Have Floridean Starch for storage -- Have Phycoerythrin Pigment (Captures blue light), which captures other wavelength and transfer energy to Chloroplast a -- Can live in deeper due Phycoerythrin, which can capture blue lights, which penetrates deeper in water -- Live deeper due to to chlorophyll b -- Can absorb shorter wavelength, but higher energy due to phycoerythrin pigment
Streptophytes --> Coleochaetales
-- Sister group to land plants -- Have plasmodesmata intercellular connections -- Have ability to protect sporophyte/eggs
Chloroplast (Green Algae)
-- Sister group to plants and plant allies -- Live in fresh water and marine environment -- Have chloroplast a/b -- Have a storage for starch -- Can be unicellular and multicellular -- Have alternation of generations
Tracheophyte/Nonseed Tracheophyte
-- Sporophyte dominant, but gametophyte are often photosynthetic -- Requires water for fertilization *EX:* Phylum Lycophyta (Club Mosses) Monilophytes (Ferns and allies below) -- Phylum Sphenophyta (Horse tails) -- Phylum Psilophyta (Whisk Ferns) -- Phylum Pterophyta (Ferns)
Plants Opportunities on land
-- Uninhabited space: Open spaces allow for more opportunity to spread and grow with sufficient food sources -- Access to sunlight: Allow to receive more food sources -- Access to more CO2 and O2: Allow plant to grow bigger -- Avoid predators/herbivores: Allow plants to get away from predators that eat them -- More minerals: Allow plants to get more food sources -- New reproduction style: Allow plants to diversify due to opportunities that were developed (Air or water reproduction)
Plants Characteristics (PAL NOTES)
-- Vascular Tissues: Need to receive nutrients and get food -- Need skeletal system: To get food and strive to be successful by getting sunlight because at competition with other plants -- Have pigments: Able to absorb more wavelength and trap different wavelengths for photosynthesis *EX:* Chlorophyll A, Chlorophyll B, Fucoxanthin, Phycoerythrin -- Need cuticle: To provide waterproofing on tissues and retain water -- Gametangia: Have to protect and enclose gametes -- Plant reproduction: New way to reproduce and be able to modify seeds -- Symbiosis: Able to provide some benefits with other species to evolve or survive *EX:* Plants and fungi symbiosis
Tracheophyte Innovations
-- Vascular tissues came from tracheid cells --> (Xylem and phloem) -- Have complex leaves, stem, and roots (specialized tissues that are plant's organs) -- Sporophyte dominant generation
Rhyniophyta
-- Was around Silurian and Devonian period -- Extinct lineage today -- First lineage of vascular plant (Have xylem and phloem due to dissection) -- Rhynie chert deposits in Scotland -- Support common ancestry of tracheophytes -- Are roughly ~20 cm in height -- Sporophyte dominant (Fossilized spores and tetrads identified) -- Has rhizomes (Underground stem w/ vascular tissues) -- Had symbiotic relationships with mycorrhizal fungi to help increase SA and absorb water/minerals -- Have stomata and cuticles
Plants Challenges on land
-- Water conservation: The ability to retain and store water -- Extreme environment: Had to overcome and survive in abnormal condition -- Skeletal support: Had to have some type of structural support to be able to get nutrients, since plants are at competition with each other -- Protection of gametes/fertilization: Had to develop ways to protect gametes and be able to reproduce -- UV radiation: Had to develop to resist against sun's UV lights
Mosses Sporophyte
--Forms out of archegonium --> calyptra (left over) archegonium --Operculum (cap) -falls off at maturity --peristome (under operculum) -peristome teeth (spore dispersal) -hydroscopoic -unevenly thickened cell walls --stomata (some mosses) --Capsule (sporangium) --Seta (stalk) Calyptra > Operculum > Peristome > Capsule > Stalk
What are the characteristic features of the hornworts?
-Hornworts are spore producing plants. -The presence of horn like capsule which gives its name hornworts. -The gametophytic plant body is thallus which is dark green, flat and lobed. -There is alternation of generation between the gametophyte in the sexual generation and the sporophyte in the asexual generation. -The sporophyte depends on the gametophyte for food and moisture and is connected with it. -The sporophyte is erect, elongate with tapering having the horn like or needle like capsule. -The sporangium splits from the top to the base which releases the spores. The pseudo elater helps in releasing the spores.
leaves of mosses and liverworts are thought to have evolved independently..an example of what?
-convergence -homoplasy
Secondary Growth
-diameter growth -- lateral, girth -vascular cambium meristem unifacial -cylinder, divies into differentiated cells
origin of land plants challenges to life on land
-gravity, -desiccation -non water-facilitated reproduction (used to use flagella -absorption of water/nutrients from soil -UV rays
renalia Synapomorphies
-reniform sporangia (bean shaped), -exarch protostele
Leptosporangium
-single layer of cell wall -less spores inside, set number of spores -annulus -only 1 initial
Monopodial Branching
1 stem (foot) advanced
Name two advantages of branched sporophytes
1) Produce more spores, 2) develop complex morphologies
Land Plant Challenges
1) Structural support -vascular tissue 2) Water movement -vascular system 3) dispersal of reproductive cells -spores 4) water retention -epidermis -cuticle 5) gas exchange stomata --> humidity, hormones, water pressure 6) anchorage/support -roots/rhizomes 7) nutrient absorption -mycorrhizae -roots
Liverwort Lifeforms (2)
1) Thallose/Thalloid (1/3 of species) -no leaf structure -dichotomous branching 2)Leafy (2/3 of species) -not true leaves -leaf like structure on body
Name two advantages of the alteration of generations life cycle
1) all alleles expressed 2) doubles opportunity to increase genetic diversit
Bryophyte Synapomorphies (after liverworts*)
1) delay in Zygotic meiosis (alt of gens) -insert mitosis after zygote --> spt 2) heteromorphic alternation of generations -interpolary theory 1)delay zygotic meiosis 2)addition of mitosis in spt -gmt dominant 3) loss of sporopollenin in zygote -heterochrony theory: change in rate/timing of development 4) nonmotile spores -no water matrix 5) cuticle 6) archegonia and antheridia -not homologous w/ chara 7) intercellular air spaces -gas exhange 8) mycorrhizae -earliest land plants -independent in multiple lineages (convergence) 9) zygote/embryo develops on gmt 10) apical meristem 11) stomates in spt* 12)Columella*
endosperm development
1) food for embryo 2) rapid mitosis with out building cell walls give liquid endosperm (like coconut milk!) 3) when cell starts producing cell walls, the endosperms becomes solid
Tracheophytes Synapomorphies* and Features - Tracheophytes > Polysporangiophytes > Embyrophytes
1) lignified tracheids* -greater heights A)tracheids (xylem) B)protostele - solid corse of vascular tissue
Mosses Synapomorphies* (after liverworts**) and Characteristics - Bryophytes > Embryophytes
1) multicellular rhizoids* -lower surface of gmt -anchorage (no water absorption) 2)stomata** 3)columella** A)hydroids B)leptoids
Livewort Synapomorphies* and Features - Bryophytes > Embryophytes
1) oil bodies* (not all have) 2) elaters* A) pores on gmt -gas exchange/different function than stomata B) Gemma Cups (asexual reproduction) -asexual propogules (mitosis) -raindrop dispersal
prevent self-fertilization
1) stamens and carpels are at different rates 2) want genetic variation 3) plants will reject their own pollen!
Monilophytes Synapomorphies* and Features (Psilophyta**)- Monilo > Euphyll > Tracheo > Poly > Embryo
1)Euphyllophyte 30kb Inversion* -molecular synapomorphy -chloroplast genome A)loss ability to produce leaves ** -convergence/homoplasy w/ cooksonia B)Protostele - end/exarch actinostele** C)Synangia (fused sporangia)** (and Marattiales) D)bifid emergence** E)1 leaf/year (sterile/vegetative parts - Ophio) F)Siphonostele (Ophio) G)secondary growth in Rhizome (ohpio) H)Radiofile secondary xylem (ophio) I)mycoheterotrophic gpt (ophio) J)root mantle (marattiales) (ophio) K)photosynthetic stem (sphenophyta) L)terminal strobilus (spheno) M)rhizomonous reproduction (spheno)
Types of Protostele
1)Haplostele 2)Actinostele 3)Plectostele
Euphyllophytes Synapomorphies * and Features - Euphyll > Tracheo > Poly > Embryo
1)Pseudomonopoldial growth* -unequal dichotomous branching -one branch is longer/more dominant A)Endarch protostele B)Fusiform Sporangia
Lignophytes Synapomorphy
1)bifacial vascular cambium -xylem to inside -phloem to outside
Polysporangiophytes Synapomorphies
1)branched spt 2)co-dominant alt of gens -gmt/spt same size -both photosynthesize
Hornworts Synapomorphies and Features
1)intercalary meristem in spt -region of undifferentiated cells -vertical growth -perpetual body of undifferentiated cells -in b/t sporangium and foot -sporangium grows from IM A)1 chloroplast w/ pyrenoid B)stomata on both gmt/spt -spt doesnt depend on gmt for nourishment -shift towardsCo-dominance D)symbiotic relationships with Nostoc
Sphenophyta Features - > Monilophyta
1)siphonostele -carinal canal --earliest tracheids/xylem --stretched quickly during growth --vascular bundle -Vallecular Canal - cortext --apoptosis
Types of Siphonostele and features
1)solenostele 2)dictyostele 3)eustele A)casparian strip B)endodermis C)pith at center D)ecto/amphiphloic
Salviniales - aquatic filicalean Synapomorphies
1)sporocarps - modified leaves -contain sori -sorus contains 1 megasporangia/multiple micro -heterosporous 2)lack anulus
Lycophytina Synapomorphy* and Features - Lyco > Tracheo > Poly > Embryo
1)spt dominant alt of gens* A)reniform sporangia B)exarch protostele - actinostele -oldest cells on outside / youngest inside -outside in development C)lateral sporangia D)emergences w/o leaf traces (enations) E)emergences w/ leaf trace to base F)microphylls w/ leaf trace into leaf G)sporangia on sporophyll (type of microphyll) H)heterospory --> endospory(i) J)unisexual gpt(i) K)ligules(i) L)secondary growth(ii) M)unifacial vascular cambium(ii)
Differences in structure between the antheridiophore and archegoniophore?
1. Male plant produces antheridiophore. 1. Female plant produces archegoniophore. 2. Antheridiophore bears the male sex organ antheridia. 2. Archegoniophore bears the female sex organ archegonia. 3. Antheridia are embedded in the upper surface of each lobes. 4. The pit like cavities having the antheridia is called the antheridial chambers. 4. The cavities where the archegonia present are known as the archegonial chamber. 5. Fertilization does not occur in the antheridiophore. 5. Fertilization occurs in the archegoniophore. 6. The sporophyte is not formed in the antheridiophore. 6. The sporophyte formation as a result of fertilization occurs.
Homosporous Plants
1. One size of spore produced in the sporangium 2. Plants are "free sporing" - i.e., they shed their spores from the sporangium 3. Each spore germinates to form a free-living gametophyte (exosporic gametophyte development) 4. Water is needed in the life cycle for the sperm to swim to the egg, but also for spore germination and gametophyte growth which takes place on the ground
Heterosporous Plants
1. Produce two sizes of spores microspores microsporangium microsporophyll megaspores megasporangium megasporophyll 2. Plants are free sporing = spores are shed from the sporangia 3. Gametophytes are endosporic-produced inside of the spore wall- two gametophytes Megagametophyte Microgametophyte 4. - Water still needed for fertilization, - but not for gametophyte growth which takes place inside of the spore wall and - not for spore germination, although needed for release of sperm
Advantages of Heterospory
1. Water not needed for gametophyte growth: endosporic gametophyte development 2. Water not needed for spore germination to form these gametophytes. 3. Insures genetic recombination: megaspores & microspores have different genes. Why? (Hint: NOT because they are large and small spores)......
Filicales
1. frond 2. vascular bundle 3. sorus 4. indusium (protective scale) 5. sporangia 6. sporangium wall 7. spores
extant lycopsids
1. sporangia are borne on sporophylls (synapomorphy) 2. dichotomous branching 3. leaves are microphylls 4. exarch xylem 5. homosporous or heterosporous
How is heterospory an advantage over homospory?
1.The gametophyte of the heterosporous ferns initiates within the spore coat so known as endosporic gametophyte. The endosporic gametophyte ensures the embryonic development than the exosporic since it is vulnerable to different environmental conditions. 2.In heterosporous pteridophytes since the megasporangium is attached to the sporophytic plant body even after fertilization. So a proper nutritive environment is created for the developing embryo better than an independent prothallus as in the homosporous ferns. 3.In heterosporous ferns after fertilization integuments become hard and form a protective cover around the female gametophyte and the embryo. This structure with advanced embryo inside forms the seed.
sori of filicales
1= sorus 2= leaflet 3= indusium (scale protecting the sorus)
seeds constist of
2 Diploid (a set of each chromosome is 1 diploid)
plant evolution
280000 plant speicies on earth. Land plants evolved from green algae
chemical formula for photosynthesis
6C02+6H20+energy (light) ---> C6H1206+6O2+6H20
synangium
A cluster of sporangia that have become fused in development
Clade:
A group consisting of an ancestor and all its descendants, a single "branch" on the "tree of life".
Taxon:
A group of one or more populations of an organism or organisms seen by taxonomists to form a unit.
leaf gap
A leaf gap is a space in the stem of a plant through which the leaf grows. The leaf is connected to the stem by the leaf trace, which grows through the leaf gap. The leaf gap is a break in the vascular tissue of a stem above the point of attachment of a leaf trace.
Synapomorphy:
A shared derived character that evolved in the common ancestor of the group = homology - one or more define clade(s)
sori
A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi.
photosystem 2 ( COMES FIRST and part of light reactions!)
ATP synthase makes ATP, electron goes through, with help of photon energy, electron transport chain to release O2 and make ATP, come BEFORE photosystem 1!
Male gametangia
Antheridium
Character:
Any observable feature, or trait, of an organism, whether acquired or inherited.
Phloem
Apical meristem that moves products of photosynthesis throughout the plant
Female gametangia
Archegonia
Chemicals
Archegonia release ___ to help sperm locate egg
-unicellular -colonial, -filamentous, -parenchymatous (cell division in 3 planes), -coenocytic (multinucleate, mitosis take place w/o cytokenesis) -cytokenisis by furrowing - haplontic and alternation of generations -marine
Basal Green Eukaryotes (plants) - Ulvophyceae
...cont.
Because they are products of meiosis. They can come from the same parent plant, but remember the results of meiosis: 4 haploid products. All genetically different because of crossing over during prophase I of meiosis.
sterile jacket
Both the antheridium and archegonium have a sterile jacket of cells, which better protects the gametes against desiccation in the terrestrial environment
1. Cuticle 2. Delayed Meiosis 3. Placental Transfer Cell 4. Stems
Bryophyte Synapomorphies
Archegonia
Bryophyte fertilization occurs within the ___
Which portion of the plant life cycle is dominant in bryophytes?
Bryophytes are the non- vascular plants which exhibits a cyclic alternation between the asexual sporophytic and sexual gametophytic generation in their life cycle. In the bryophytes the sporophyte lives as attached to the gametophytic plant body. Dominant generation is the gametophytic plant body is haploid which is concerned with the production of gametes.
characteristics of bryophytes
Bryophytes are the plants growing in moist and shady places. Bryophytes are thalloid organisms with simple multicellular body. Bryophytes are known as the non- vascular plant since the xylem and phloem is absent. They do not have root, stem or leaves. It possesses a stem, root and leaf like structure; root like structure is known as the rhizoids. The plants are green possess chloroplast and they are autotropic. Bryophytes are considered as the amphibians of the plant kingdom. Reproduction occurs both by vegetative and sexual methods. The vegetative reproduction occurs by formation of gemmae, protonema and bulbils. Sexual reproduction is oogamous which involves gametogenesis and syngamy. Antheridia are club shaped and stalk like structure with a sterile sheath called the jacket. Antheridium encloses sperms or antherozoids. Archegonia are flask shaped structure having the stalk, the venter and the neck. The Venter encloses the single egg and the. venter canal cell. The zygote represents sporophytic generation which transforms to oospores. The sporogonium is concerned with the production of spores. Water is essential for the fertilization.
cellular respiration
C6H12O6 + O2 → CO2 + H2O + Energy
Method by which water and nutrients are distributed in nonvascular plants
Capillary action
- apical cell - reproductive structures = antheridia (sperm) surrounded by sterile layer of cells - oogonium (egg) w/ crown cells at end
Chara
Compare spores of charophytes and Embryophytes.
Charophytes: lack sporopollenin and are flagellated and depend on water for dispersal and fertilization. Embryophytes: have sporopollenin allowing them to be dispersed through dry air without harm.
-Zygote nourished by thallus
Choleochates Synapomorphy
- full fledged phragmoplast - plasmodesmata - oogamy
Choloeochates and Chara Synapomorphies
Gemmae
Clumps of cells in "cups" that detach from a parent and develops into a new individual
Sori
Cluster May be naked or protected by indusium or false indusium
Strobilae
Clusters of sporophylls are called ___
- chlorophyl a - phycobilins (accessory pigments/light capturing?) - phycobilisomes (protein complexes anchored to thylakoid membranes) - photosystems I & II - H2O is the electron donor in photosynthesis
Cyanobacteria synapomorphies
Liverwort sexual reproduction
Dioecious antheridia produced on an antheridiophore (male) archegonium produced in a archegoniophore (female)
How does Oogamy lead to Egg retention?
Egg cell protected and retained on mother plant until after fertilized egg cell (zygote) divides into haploid spores which are then released
Seeds
Embryos packaged with a supply of nutrients within a protective coat; found in land plants
Bryophyte adaptions to life on land
Epidermis (reduce water loss) Cuticle (reduce water loss) Air pores to stomata (gas exchange) Spores (thick resistant walls for wind dispersal)
pseudomonopodial growth
Euphyllophytes Synapomorphy
clades of Tracheophytes
Euphyllophytina, Lycophytina, Rhyniopsida
Eusporangia vs. Leptosporangia
Eusporangia a)from meristematic cells b)+2 cell layers in sporangium wall c)many spores d)no annulus Leptosporangia a)1 meristematic cell b)1 cell layer c)fewer spores d)annulus
Phylogeny:
Evolutionary history of a group of organisms
Pteridophyta Clade
Ferns
Pterophytes
Ferns, whisk ferns and horsetails belong to this phylogenetic group
crozier (fiddle head)
Fiddleheads are the furled fronds of a young fern,[1]
Protonema
Filamentous to platelike horizontal growth formed from meiospores produces buds (bulbils) which grow into leafy gametophytes
Leaves
Flattened photosynthetic structures arising from stems or branches, with vascular tissue
Liverwort Sporophyte Parts
Foot (anchors and absorbs nutrients) Seta (elongates) Capsule (meiosporangia)
Dichotomous Branching
Forks same length
Vascular
Fossils suggest that ___ plants share a common ancestor with tall, branched sporophytes
Label B
Gametophyte
Embryophyte problems: Increased energy cost?
Gave rise to a Placental transfer cells
Heterotrichous
Having both horizontal and ariel growth
Phylogenetic name for liverworts
Hepatophyta
Mosses Life Cycle
Heteromorphic Alt of Generations (gmt dominant) --germinated spore --> protonema -filamentous stage (forms gmt thru mitosis) --antheridiophores/archegoniophores -paraphyses in b/t antheridia/archegonia
Liverwort Life Cycle
Heteromorphic Alt of Generations (gmt dominant) --oogamous --male/female gmt -antheridiophore (n) -archegoniophore (n) --sporophyte (2n) on/embedded in gmt -directly out of archegonium -foot provides nourishment from gmt -placental transfer cells (plasmodesmata) -archegonium encloses sporangium
Vascular plants that produce two types of spores
Heterosporous
megaspores, microspores
Heterosporous plants produce two distinct types of spores: ___ and ___
homospory vs. heterospory
Homospory = sporangium - pro: both sexes easily accessible, can always fertilize, more spores, greater dispersal - con: gpt develops outside the spore, less genetic diversity Heterospory = megasporangium (egg) and microsproangium (sperm) - pro: gpt inside spore, genetic diversity - con: have to be close to interact, more energy needed, less spores
Rhizomes
Horizontal extensions of stem that anchor plants to soil; precursor to roots
intercalary meristem in sporophyte
Hornworts Synapomorphy
Early earth 4.5 billion years ago
Hot, meteorites, lightning storms, magma · Initial atmosphere not conducive to life - 2 billion years ago oxygen starts building in atmosphere b/c of cyanobacteria
~470 million years ago
How long ago did non-vascular plants arise?
~425 million years ago
How long ago did vascular plants arise?
Protonema
If bryophyte spores land somewhere moist, they undergo mitosis and form multicellular threads called ___
endarch
In endarch development the protoxylem begins its development from the innermost procambial cells located adjacent to the pith and development progresses outward. Therefore, the protoxylem is found toward the inside and metaxylem toward the outside of the stem. Endarch development is considered the most highly advanced type of primary xylem development
exarch
In exarch development the protoxylem begins development from the outermost edge of the procambial cylinder (the side closest to the stem) and development proceeds from the outside to the inside. Therefore, the protoxylem is found toward the outside and metaxylem toward the inside of the stem. This type of primary xylem development is considered a primitive condition in vascular land plants
Megaphylls
In horsetails, leaves are simplified ___
Gametophytes
In mosses and nonvascular plants, ___ are long lived and photosynthetic
Difference between a calyptra and an operculum
In mosses plant calyptra is a cup shaped structure which is formed from the archegonium. The calyptra is attached to the capsule which will protect the sporophyte and it will fall off after the capsule matures. Whereas the operculum is an apical portion of the moss capsule which is also a cup shaped structure. The operculum is also known as the lid of the capsule and is the terminal end of the capsule.
What is the function of the operculum?
In mosses the capsule is covered by a lid like structure which is known as the operculum. The operculum will fall off when the spore becomes mature. The calyptra is a structure which protects the operculum.
Sporophyte
In vascular plants, the large, obvious plant is the ___
Endarch
Inside outward old xylem on inside
Interpolation Theory
Interpolation Theory suggests that the sporophyte generation progenated from a haploid, green algal thallus in which repeated mitotic cell divisions of a zygote produced an embryo retained on the thallus and gave rise to the diploid phase (sporophyte). Ensuing evolution caused the sporophyte to become increasingly complex, both organographically and anatomically.
-secondary growth -unifacial vascular cambium
Isoetales/lepidodendrales Synapomorphies
Liverworts
Lack stomata and are believed to be the first land plants
Sporophyte
Land plant embryos develop into a ___ within an archaegonium
Vascular tissue, Seeds
Land plants can be categorized by the presence of absence of ___ and ___.
Nonvascular plants
Land plants with dominant gametophyte generation
Megaphyll
Leaf morphology with a branched system of vascular tissue
Filiciales Features > Monilophyta
Leptosporangia grouped in Sori -indusium - cover -false indusium - edge of leaf folded over -exindusiate - no indusium Homosporous Antheridia develop first (unisexual) -then archegonia later (becomes bisexual) -fertilize o/t ferns before self Autotrophic Gpt
Filicales = leptosporangiate ferns
Leptosporangiate ferns are the largest group of living ferns, including some 11000 species worldwide.[1] They constitute the subclass Polypodiidae,[2][3] but are often considered to be the class Pteridopsida or Polypodiopsida,[4] although other classifications assign them a different rank.[5] The leptosporangiate ferns are one of the four major groups of ferns, with the other three being the Eusporangiate ferns comprising the marattioid ferns (Marattiidae, Marattiaceae), the horsetails (Equisetiidae, Equisetaceae), and whisk ferns and moonworts.[3][4] There are approximately 8465 species of living leptosporangiate ferns, compared with about 2070 for all other ferns, totalling 10535 species of ferns.[2] Almost a third of leptosporangiate fern species are epiphytes.[6] These ferns are called leptosporangiate because their sporangia arise from a single epidermal cell and not from a group of cells as in eusporangiate ferns (a polyphyletic lineage). The sporangia are typically covered with a scale called the indusium, which can cover the whole sorus, forming a ring or cup around the sorus, or can also be strongly reduced to completely absent. Many leptosporangiate ferns have an annulus around the sporangium, which ejects the spores.
Sporangial Types
Leptosporangium Eusporangium
Bryophyte life cycle
Like all plants, the bryophyte life cycle has an alternation of generations between a diploid sporophyte (2n) and a haploid gametophyte (n). In the bryophytes, unlike the other plants, the dominant, indeterminate generation is the gametophyte, whereas the sporophyte is determinate (once formed, there is no further development) and nutritionally dependant on the gametophyte. diploid sporophyte (2n) meiosis produces haploid spores (n) haploid spores germinate (mitosis) into haploid thallus (n), the gametophyte, which can reproduce asexually by gemmae cups containing gemmae or sexually with gametangiophores. fertilization of egg by sperm produces a diploid zygote (2n) which divides by mitosis into new sporophyte. The male gametangiophore is called an antheridiophore; it grows up from the thallus and consists of a stalk with a flat-topped head.The flat top portion is called the antheridial head. Imbedded in the upper surface of the antheridial head, there are antheridia full of flagellated sperm; when it rains, the sperm are spilled out onto the surface and washed off onto the ground. The female gametangiophore is called an archegoniophore; it grows up from the thallus and consists of a stalk and an archegonial head with pendant (hanging) lobes or fingers. On the underside of the head are archegonia, each of which is like an inverted vase and holds a single haploid egg. Rain drops hit the ground and splash water carrying sperm up to the archegonia, which face downwards. The sperm swim up the tube of the archegonium and fertilize the egg. The zygote (fertilized egg) divides by mitosis, and a diploid sporophyte plant grows. Nutrients are supplied to the developing sporophyte by the gametophyte. A large, egg-shaped sporangium forms at the apex of the sporophyte. Meiosis occurs inside the sporangium and hundreds of haploid spores are produced. When the spores are released, they disperse. The spores that land in a suitable habitat germinate and grow the next generation of gametophytes. Thus, the cycle continues.
Difference between liverworts and moss
Liverworts are thallose and leafy bryophytes. They are found in the temperate forest and on the shades. The gametophytic generation is prominent which flat, ribbon like with rhizoids is. The plant body carries out photosynthesis. Sporophyte is a spherical structure which grows parasitic on the gametophytic plant body. Examples: Riccia, Marchantia. In the mosses the gametophytic generation is the prominent one. It has a simple stem and root like rhizoids and leaf. The gametophyte is an independent organism. The gametophytic when attains maturity develops the male and the female sex organs at the tip of the stem. It after syngamy produces the zygote which later give rise to the diploid sporophyte. The sporophyte lives as a parasite on the gametophytic plant body. The sporophyte bears the capsule which produces haploid spores. These spores under favourable condition form the green filamentous protonema which grows to stem of gametophyte. -
Fragmentation of gametophytes and gemmae
Liverworts can reproduce asexually by ___ and ___
Bryophytes
Liverworts, mosses, hornworts
Sphenophyta
Living horsetails are represented by about twenty herbaceous species in the single genus Equisetum.[4] They typically grow in wet areas, with whorls of needle-like branches radiating at regular intervals from a single vertical stem. The vascular bundles trifurcate at the nodes, with the central branch becoming the vein of a microphyll, and the other two moving left and right to merge with the new branches of their neighbours.[7] The vascular system itself resembles that of the vascular plants' eustele, which evolved independently and convergently.[7] Very rapid internode elongation results in the formation of a pith cavity and a ring of carinal canals formed by disruption of the primary xylem. Similar spaces, the vallecular canals are formed in the cortex.[7] Due to the softer nature of the phloem, these are very rarely seen in fossil instances.[citation needed] In the Calamitaceae, secondary xylem (but not secondary phloem) was secreted as the cambium grew outwards, producing a woody stem, and allowing the plants to grow as high as 10m. All extant species of Equisetum are herbaceous, and have lost the ability to produce secondary growth.[7] The underground parts of the plants consist of jointed rhizomes, from which roots and aerial axes emerge. The plants have intercalary meristems in each segment of the stem and rhizome that grow as the plant gets taller. This contrasts with the seed plants, which grow from an apical meristem - i.e. new growth comes only from growing tips (and widening of stems). Sphenophytes bear cones (technically strobili, sing. strobilus) at the tips of some stems. These cones comprise spirally arranged sporangiophores, which bear sporangia at their edges, and in extant sphenophytes cover the spores externally - like sacs hanging from an umbrella, with its handle embedded in the axis of the cone. In extinct groups, further protection was afforded to the spores by the presence of whorls of bracts - big pointed microphylls protruding from the cone. The extant horsetails are homosporous, but extinct heterosporous species such as Calamostachys casheana appear in the fossil record.[8] The sporangia open by lateral dehiscence to release the spores. The spores bear characteristic elaters, distinctive spring-like attachments which are hygroscopic: i.e. they change their configuration in the presence of water, helping the spores move and aiding their dispersal.
Club mosses, spike mosses and quillworts belong to this phylogenetic group
Lycophyta
-heteromorphic alternation of generations -spt dominant
Lycophytina Synapomorphies
-Eusporangiate -Homosporous
Lycopodiaceae Synapomorphies
-Sporangia borne on sporphylls -dichotymous branching - leaves are microphylls - exarch xylem - homosporous or heterosporous
Lycopsida Synapomorphies
Sporopollenin
Makes walls resistant to decay and drying
Sporangium
Meiosis occurs in a ___ (at the tip of the sporophyte), forming haploid spores
Lignin
Molecule in cells of the xylem that provides structural support to large sporophyte
-multicellular rhizoids
Moss Synapomorphy
-Gametophyte dominant (heteromorphic) -Oogamy
Mosses Life Cycle
Nonvascular
Mosses, hornworts and liverworts belong to what kind of land plants?
Bryophytes
Mosses, hornworts, and liverworts make up a paraphyletic group called ___.
Homosporous
Most ferns are homosporous/heterosporous?
homosporous
Most seedless vascular plants, and all non-vascular plants, are ___
Bryophytes
Non vascular cryptogams (small plants)
No flagella
Non-motile spores
Label A
Nonvascular
Hornworts (Anthocerophyta)
Nonvascular plant with large, flat plates of gametophytes that contain cavities full of nitrogen-fixing cyanobacteria
Bryophytes
Nonvascular plants where gametophytes are dominant
fruit
ONLY ANGIOSPERMS. ovary of the plant!, begin to developt after pollenation triggers hormonal changes and wall of ovary becomes thick
vascular plants
ONLY pteridophytes, gymnosperms and angiosperms
Equisetum stem
One of a number of large, air-filled, intercellular channels running the length of each internode and positioned approximately between the vascular bundles. They lie outside and are larger than the carinal canals.
Bryophyte characteristics common with land plants
Oogamous (egg and sperm) Gametangia are multicellular Zygote, embryo, and young sporophyte (nourished by female gametophyte) Multicellular sporophyte Multicellular sporangia Spores with walls containing sporopollenin
What is Oogamy and what is it the result of?
Oogamy is the where the fertilization of a large sessile Egg by a smaller, motile sperm. It is the result of tissue differentation
Is operculum haploid or diploid?
Operculum is the diploid part of the sporophyte.
Roots
Organs that absorb water and nutrients from the soil, as well as anchor plant in the soil
Label E
Ovaries and Flowers
Bryophytes, Monophyletic or Paraphyletic?
Paraphyletic
Seedless vascular plants
Paraphyletic group whose traits include swimming sperm, no seeds, and is usually homosporous
What is the function of the peristome?
Peristome is present inside the capsule of the moss sporophyte. When the sporophytes mature the calyptra and the operculum also falls off exposing the peristome teeth. They are tiny tooth like structures found at the mouth of the capsule. It can be seen as one or two rows and this remain closed during the wet season and they get exposed during the dry season.
Endosymbiotic origin of plastids and mitochondria
Phagocytosis: cell engulfs aerobic bacterium --> mitochondria and then photosynthetic bacteria --> chloroplast o These organelles have... - A double membrane - Can replicate independently inside the cell - Have their own circular DNA (like bacteria)
What process does the sporangium not undergo?
Photosynthesis therefore it is parasitic b/c if it can't make it's own food it will use the gametophyte's.
Bryophytes
Plants that are restricted to moist habitats and are usually very short
Archaeplastida Synapomorphies
Plastid derived from primary endosymbiosis
-branched sporophyte -codominant alternation of generations
Polysporangiophytes Synapomorphies
Heterospory
Production of two types of spores megaspore - larger, female microspore - smaller, male Formed in different sporangia
Pros and Cons of a waxy cuticle?
Pros: Minimizes water loss and prevents plant from desiccation. Protection from UV rays that can cause mutations. while allowing light to enter Cons: Limits gas exchange essential for respiration and photosynthesis. No protection against heat
buds, gametophytes
Protonema form photosynthetic ___ that develop into ___
Psilotum
Psilotum superficially resembles certain extinct early vascular plants, such as the rhyniophytes and the trimerophyte genus Psilophyton. The unusual features of Psilotum that suggest an affinity with early vascular plants include dichotomously branching sporophytes, aerial stems arising from horizontal rhizomes, a simple vascular cylinder, homosporous and terminal eusporangia and a lack of roots.[3] Unfortunately, no fossils of psilophytes are known to exist. A careful study of the morphology and anatomy suggests that whisk ferns are not closely related to rhyniophytes, and that the ancestral features present in living psilophytes represent a reduction from a more typical modern fern plant. Significant differences between Psilotum and the rhyniophytes and trimerophytes are that the development of its vascular strand is exarch, while it is centrarch in rhyniophytes and trimerophytes.[4] The sporangia of Psilotum are trilocular synangia resulting from the fusion of three adjacent sporangia,[4] and these are borne laterally on the axes. In the rhyniophytes and trimerophytes the sporangia were single and in a terminal position on branches.[5]
Elators
Pterophyta adaptation for spore dispersal in air
Rhizoid
Root-like ___ secure developing gametophytes to the ground
Streptophyte synapomorphyresponsible for Controlled directionality of cell growth (plant form)
Rosette-Proteins
Label C
Seedless
___ ___ plants were extremely abundant ~300 million years ago, forming massive forests
Seedless vascular
Spore release Liverworts
Seta elongates Capsule open irregularly releasing spores wind disseminated
Rhizoids
Simple filaments of cells that absorbed water and nutrients from the soil
amphiphloic solenostele (all ferns)
Siphonosteles can be ectophloic (phloem present only external to the xylem) or they can be amphiphloic (with phloem both external and internal to the xylem. Among living plants, many ferns and some Asterid flowering plants have an amphiphloic stele. An amphiphloic siphonostele can be called a: solenostele - if the cylinder of vascular tissue contains no more than one leaf gap in any transverse section (i.e. has non-overlapping leaf gaps). This type of stele is primarily found in fern stems today. dictyostele - if multiple gaps in the vascular cylinder exist in any one transverse section. The numerous leaf gaps and leaf traces give a dictyostele the appearance of many isolated islands of xylem surrounded by phloem. Each of the apparently isolated units of a dictyostele can be called a meristele. Among living plants, this type of stele is found only in the stems of ferns.
Pterophytes
Sister clade to seed plants
Phylogenetic name for seed plants
Spermatophyta
Label C
Sporangia
Eusporangium
Sporangium develops from 2+ initial cells jacket cell layer is 2+ layers thick Most common
Leptosporangium
Sporangium develops from a single initial cell jacket cell layer is only one cell thick Most ferns
sporophyll
Sporophyll =Leaf that bears sporangia · Sporangia lays right on top of leaf Microphyll = A leaf that has a single vein in it · Sporophyll is also a microphyll but specialized
Modified leaves of a sporophyte that bear sporangia
Sporophylls
In mosses and vascular plants, ___ are shorter lived, and nutritionally dependent on gametophytes
Sporophyte
Label A
Sporophyte
Streptophyta - CharophyceanAlgae
Streptophyta = monophyletic (includes embryophytes) Charophycean Algae = paraphyletic - zygnematales -choleochates - chara
Gametophytic Iteroparity
Streptophyte synapomorphy: During reproduction, only the gametes are used up, while the original parent plant is capable of continued growth and reproduction.
- chlorophylls a + b - starch stored in chloroplasts - 2-7 thylakoids stacked in grana - loss of phycobilins/phycobilisomes
Synapomorphies of Basal Green Eukaryotes (plants)
- loss of sporopollenin in zygote, now in cell walls - nonmotile spores - cuticle - archegonia and antehrideia w/ steril jacket of cells
Synapomorphies of land plants
indusiate
That the indusium is a _special_ organ, i.e. not an eruption of the cuticle, I am sure; hence it is essential to examine extensively both indusiate and other forms, the precise extension of their veins, etc. at an early period to ascertain if their most diversified situations cannot be reduced to some one type.
Marattiales
The Marattiaceae is one of two groups of ferns traditionally known as eusporangiate fern,[2] meaning that the sporangium is formed from a group of cells vs the leptosporangium in which there is a single initial cell. There have long been four traditional extant genera (Angiopteris, Christensenia, Danaea and Marattia), but recent genetic/cladistic analysis [3] has determined the genus Marattia to be paraphyletic, and the genus has been split into three genera, the two new ones being Eupodium and Ptisana. This fern group has a long fossil history with many extinct taxa
Relationship between an antheridium and an antheridiophore?
The antheridium is the male sex organ which is borne inside the antherdial chamber of the antheridiophore. So antherdia is the male sex organ where as the antheridiophore is the male gametangiophore.
What occurs during Delayed Meiosis?
The diploid zygote will delay meiosis and instead undergo mitosis while being retained and protected by the haploid gametophyte.
Liverwort life cycle
The life of a liverwort starts from the germination of a haploid spore to produce a protonema, which is either a mass of thread-like filaments or else a flattened thallus.[14][15] The protonema is a transitory stage in the life of a liverwort, from which will grow the mature gametophore ("gamete-bearer") plant that produces the sex organs. The male organs are known as antheridia (singular: antheridium) and produce the sperm cells. Clusters of antheridia are enclosed by a protective layer of cells called the perigonium (plural: perigonia). As in other land plants, the female organs are known as archegonia (singular: archegonium) and are protected by the thin surrounding perichaetum (plural: perichaeta).[7] Each archegonium has a slender hollow tube, the "neck", down which the sperm swim to reach the egg cell. Liverwort species may be either dioicous or monoicous. In dioicous liverworts, female and male sex organs are borne on different and separate gametophyte plants. In monoicous liverworts, the two kinds of reproductive structures are borne on different branches of the same plant.[16] In either case, the sperm must move from the antheridia where they are produced to the archegonium where the eggs are held. The sperm of liverworts is biflagellate, i.e. they have two tail-like flagellae that enable them to swim short distances,[17] provided that at least a thin film of water is present. Their journey may be assisted by the splashing of raindrops. When sperm reach the archegonia, fertilisation occurs, leading to the production of a diploid sporophyte. After fertilisation, the immature sporophyte within the archegonium develops three distinct regions: (1) a foot, which both anchors the sporophyte in place and receives nutrients from its "mother" plant, (2) a spherical or ellipsoidal capsule, inside which the spores will be produced for dispersing to new locations, and (3) a seta (stalk) which lies between the other two regions and connects them.[17] When the sporophyte has developed all three regions, the seta elongates, pushing its way out of the archegonium and rupturing it. While the foot remains anchored within the parent plant, the capsule is forced out by the seta and is extended away from the plant and into the air. Within the capsule, cells divide to produce both elater cells and spore-producing cells. The elaters are spring-like, and will push open the wall of the capsule to scatter themselves when the capsule bursts. The spore-producing cells will undergo meiosis to form haploid spores to disperse, upon which point the life cycle can start again.
Ophioglossales
The plants have short-lived spores formed in sporangia lacking an annulus, and borne on a stalk that splits from the leaf blade; and fleshy roots. Many species only send up one frond or leaf-blade per year. A few species send up the fertile spikes only, without any conventional leaf-blade. The gametophytes are subterranean. The spores will not germinate if exposed to sunlight, and the gametophyte can live some two decades without forming a sporophyte. Contains to rows of fused sporangia
rhizoids
The thallus is anchored to the substrate by rhizoids. A rhizoid is a hair-like structure that may be only one cell wide, though it can be more than one cell in length. There is no root in any bryophyte!
sporophyte thallus (moss)
The thallus is determinate; having a specific final body size. Moss sporophytes consist of the haustorial foot (nutrition exchange area), a supporting (seta) stalk (with hydroids and leptoids), and (sporangium) capsule.
mycoheterotroph
These plants obtain nutrients from mycorrhizal fungi that are attached to the roots of a vascular plant.
Sporophylls
This derived trait allows vascular plants to produce many more spores than nonvascular plants
Lycophyta
This phylogenetic group has microphylls only, strobiliae, and most are homosporous
Horsetai
This pterophyte has strobiliae
Monophyletic clade that includes all vascular plants
Tracheophyta
lignified tracheids
Tracheophytes Synapomorphy
True
True or false: Gametophytic Semelparity is demonstrated in Chlorophytes and below
True
True/false: Heterosporous seed plants are either male or female, but not both
True
True/false: all seed plants are heterosporous
False
True/false: heterosporous plants produce gametophytes that are both male and female
False
True/false: lycophyta have megaphylls
True
True/false: pterophyta spores can develop into gametophytes far from their parent sporophyte
True
True/false: there is enough air pressure inside a mature sporangium that spores can explode outward
True
True/false: water is needed for bryophyte reproduction
Vascular Tissue
Tube-like cells that transport water up from soil and photosynthetic products down from photosynthetic structures in land plants
- One of the largest single celled organisms - 2n nucleus (vegetative stage) "multinucleate" but still single celled
Ulvophyceae - Acetabularia (mermaids wine cup)
Liverwort Sporophyte Development
Under side of archegoniophore where the archegonia were
Label B
Vascular
Homosporous
Vascular plant that produces a spore with both male and female gametophytes
Homosporous
Vascular plants that produce one type of spore
1. Rosette proteins. 2. phragmoplast
What are the primary synapomorphies for the Streptophyte Clade?
1a. Plasmodesmata 1b. Intercellular Communication Plasmodesmata allow information to flow from one cell to another, which allows for the development of Multicelluarity
What does the formation of a Phragmoplast give rise to?
Mitotic division of the zygote to form a multicellular sporophyte amplifies the sexual product (# haploid spores) since many diploid cells will be able to undergo meiosis. ==> ENHANCING survival rate in unfavorable conditions.
What would be the adaptive advantages of delaying meiosis and forming a multicellular sporophyte?
Node:
Where lineages split / a common ancestor
Label D
With Seeds
Apical meristem that moves water and minerals up from soil and to the rest of the plant
Xylem
Name two types of tissue specialized for transporting fluid and dissolved materials in vascular plants
Xylem, Phloem
Spherical
Young sporangium are ___ in shape
-Reproduction through conjugation: two filaments lien up next to each other recognize each other w/ pheromones - "protuberances" bulge out of each filament towards the other and form a "conjugation tube" --> Cell contents move from one filament over to the other o One always gets emptied out and the other receives o Nuclei fuse in the receiving filament and form a diploid zygote
Zygnematales - Spirogyra
Seedless Vascular
___ ___ plants had dramatic effects on carbon cycling in the atmosphere, and a large impact on global climate on ancient Earth
Sporophytes
___ are nutritionally dependent on and physically attached to a gametophyte of a land plant
homoplasy
a character that has evolved more than once in unrelated organisms
Outgroup:
a monophyletic group of organisms that serve as a reference group when determining the evolutionary relationship among monophyletic groups of organisms. o Always the one that diverged first o Usually one taxa but could be more
example of a haploid
a sperm would be a haploid, for example pollen is a haploid (1n)
siphonostele
a stele consisting of a core of pith surrounded by concentric layers of xylem and phloem.
paraphyses
a sterile hairlike filament present among the reproductive organs in many lower plants, especially bryophytes, algae, and fungi.
leaf trace
a strand of conducting vessels extending from the stem to the base of a leaf.
indusium
a thin membranous covering, especially a shield covering a sorus on a fern frond.
fern rhizomes
all have solenosteles (siphonostele thats amphiphloic with a leaf gap)
Homospory
all the same size all spore produce the same type of gametophyte
Synapomorphies of Euphyllophytina and Lycophytina
alternation of generations with spt dominant
chlorophyll
always starts light reactions, green pigment in plants
Sister Taxa:
any taxa derived from a common ancestral node. o Two last taxa - closest related o A pair o Usually only one pair on tree
Polysporangiophytes
are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that terminate in sporangia. The name literally means many sporangia plant. The clade includes all land plants (embryophytes) except for the bryophytes (liverworts, mosses and hornworts) whose sporophytes are always unbranched. While the definition is independent of the presence of vascular tissue, all living polysporangiophytes also have vascular tissue, i.e., are vascular plants or tracheophytes. Fossil polysporangiophytes are known that have no vascular tissue, and so are not tracheophytes.
mycorrhizal relationships
arose independently in major plant lineages
Embryophyte Problem: Spore Dispersal
bottom of sporophyte continues to divide mitotically to push sporangium up--- development of the stem
Synapomorphies of Polysporangiophytes
branched sporophyte; codominant alternation of generations
Phylogenetic tree:
branching diagram that represents phylogenetic relationships - represent hypotheses of relationships
petals
brightly colored to attract pollinators,
main groups of plants
bryophytes (mosses) pteridophytes (ferns) gymnosperms (pines) angiosperms (flowering)
leptoids
carbohydrate conducting cells
3 Mini Steps of Calvin Cycle: carbon fixation #1
carbon fixation, CO2 attaches to RuBP by an enzyme, makes carbon molecule
heterochrony
change in rate or timing of development
color
colors we see are determined by our eyes detecting color waves, what we see are reflected colors and everything else is absorbed by that color,
cyclic electron pathaway (part of light reactions!)
creates ATP only, no NADPH or O2 produced, goes through photosystem photosystem 1 ONLY
cyanobacteria endosymbiosis
cyanobacteria layer in lichen (gives lichen fixed carbon) Cycad roots w/ anabaena + nostoc (gives cycad fixed nitrogen)
Bryophyte Synapomorphies
delay in zygotic meiosis, heteromorphic alternation of generations, loss of sporopollenin in zygote, nonmotile spores (with sporopollenin), cuticle, archegonia and antheridia, intercellular air spaces, mycorrhizae embryo develops on gametophyte, apical meristems
Telome Theory for Megaphyll Evolution
dichotomous branching with telomes --> (over-topping) dominant branch/telome -->(planation) 1 plane --> (webbing) leaf tissue fills in
Calvin Cycle (aka dark reactions!)
do not require light, everything goes in, use ATP and NADPH to create sugar from CO2.
bisexual gametophyte
each gametophyte has both antheridia and archegonia
photoexcitation of chlorophyll (light reactions)
electrons in pigment absorb energy and move to excited state, electrons spontaneauly return to lower UNLESS electron is passed to another molecule while excited
plant basics (in all types of plants)
eukaryotic, multicellular, photoautotrophic, cell walls of cellulose and chlorophyll a and b, apical meristem
euphyll (leaf with branched veins) moniliphyte inversion
euphyllophytes Synapomorphy
Moniliformopses = monilophytes
evolution of megaphylls Psilophyta Ophioglossales Marattiales
carpel
female reproductive part, sticky stuff for pollen to land on
Megaspores develop into ___ gametophytes, which produce only ___
female, eggs
Most pterophytes are ___
ferns
Filicales anatomy
fiddlehead= crozier leaf = frond
photolysis (light reactions)
first step of photosyntehsis, water is split into H and O, O2 is released out of photosynthesis, as water is split in this stage, electrons are removed and their energy is increased by light (photons!), these will eventually reduce CO2
angiosperms
flowering plants, vascular tissue, seeds are enclosed, 250000 known species, seeds or fruit are enclosed, double fertilization, VERY abundant
stroma
fluid inside chloroplast
Liverwort asexual reproduction
gemmae in gemma cups located on dorsal (upper) surface dispersed by raindrops (splash cup mechanism)
binomial nomenclature
genus + specific epithet
photoautotrophs
get energy from sunlight (plants, algae, some protsits and some bacteria)
Parenchyma
ground tissue with no specialized function -it's cells produce metabolic products and retain their ability to specialize
multiple fruit
groups of flowers tightly clustered like PINEAPPLE.
Sporophytes produce spores that are
haploid and genetically variable
Delay in zygotic meiosis
haplontic to alternation of generations
hydrophyte
have a lot of air sacs so they can float on water
gymnosperms
have naked seeds, NO FLOWERS, pines, vascular tissue, double fertilization
Cuticle
helps prevent desiccation
synapomorphies of Selaginellales, Isoetales, Lepidodendrales
heterospory endospory unisexual gametophytes ligules
Lycopodiaceae life cycle
homosporous; sporophyte dom
photosynthesis
how plants derive energy from sunlight, reducing Co2 for energy like glucose to come out (c6h1206). Co2 goes in o2 comes out occurs in CHLOROPLASTS or green parts of the plants, water goes in and out!, Co2 is reduced to glucose
some mosses have...
hydroids (water conducting cells) and leptoids (carbohydrate conducting cells)
chlorophyll
in ALL plants-pigment that makes plant green, best absorbs red and blue, least absorbs green
electron transport chain
in thylakoid membrane in mitochandria, eletron transport chain pumps porton in thylakoid space and moves them across membrane, they create ATP, reductase adds the e- to create NADPH
Hornwart Synapomorphy
intercalary meristem in sporophyte
strobilus
is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but many botanists restrict the use of the term cone to the woody seed strobili of conifers. Strobili are characterized by a central axis (anatomically a stem) surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems.
microphylls
is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap.
Three types of gametes among green algae
isogamy = same size, both motile anisogamy = different sizes, both motile oogamy = different sizes, egg nonmotile
Nonvascular
lack true xylem and phloem
Petiole
leaf stem
light energy
light energy travels in waves
photon
light paritlce that gives electrons energy
Synapomorphy of Tracheophytes
lignified tracheids
Bryophytes include...
liverworts, mosses, hornworts gpt dominant, sterile jacket around archegonia & antheridia, spy development in archegonia, spy dependent on got, all parts haploid except zygote
apical meristem
localized regions of cell division at tips of shots and roots of embryos. (where cells divide quickly!)
wavelengths
longer wavelengths have less energy, shorter wave lengths equal MORE energy
Psuedomonopodial Branching
looks like monopodial branching starts out dichotomous 1 doesn't grow and the other overtops it
light reactions more
make ATP (only for next step to use, they do not make any net gain of ATP), require light energy and split up H20, generate NADPH (electron carriers in photosynthesis
ATP synthase
makes ATP
stamens
male reproductive part of flower, it is short for no self fertilization, also "yellow" stuff, pollen
Microspores develop into ___ gametophytes, which produce only ___
male, sperm
Lycopodium roots
may emerge at any point along the stem, or from the base of the stem
epidermal layers of the moss gametophyte
may possess cutin to prevent desiccation in the terrestrial environment, if so, the thallus then needs pores to allow for gas exchange. In some mosses the pores are surrounded by a single "doughnut shaped" guard cell. In others we may find truly functional stomata.
thylakoid membrane
membrane in which photosynthesis happens (this is located in chloroplasts)
Leaf morphology with a single strand of vascular tissue
microphyll
Two basic leaf morphologies
microphylls/megaphylls
Phragmoplasts
microtubules orient the ER and the vesicles across the middle of the dividing cell.
sepals
modified leaves that enclose flower and protect it, they are green
2 types of spore tetrads
monolete, trilete
bryophytes
moss (tiny green stuff) no vascular tissue (don't grow tall), no seed or flower or fruit
Basal Green Eukaryotes (micromonas)
most are motile, contain a single chloroplast (w/ pyrenoid and eyespot), and lack a cell wall
Moss Synapomorphy
multicellular rhizoids
dicots
netlike vanes (oak trees or roses))
do plants go through anaerobic respiration?
no. water will be present in plants.
light reaction summary
noncyclic e- flow takes e- from H20, ATP and NADPH are produced, cyclic flow ONLY produces ATP. ADP, H20, and NADP+ go in, ATP NADH and O2 come out
why 2 pathaways?
noncyclic flow produces ewual amount of ATP and NADPH, Calvin CYcle needs more ATP,
heterotrophs
not self feeders
Significance of endosymbiotic acquisition of chloroplasts
o All of the chloroplasts in Plantae may be descended from a single event - Chloroplast = bacterium? - Chloroplasts evolved from photosynthetic bacteria - more evidence: ribosomes in plastids are identical to those in cyanobacteria - two membranes around chloroplast could be one from cyanobacteria and one from eukaryote
mychorizzal associations
o From a symbiosis w/ a root (mutualism - both parties benefit) - Fungus gets a home, roots get fixed carbon, tree/shrub gets nutrients o May have been necessary for plants to movement onto land from aquatic systems o Have arisen independently many times in plant lineages
Intercellular air space for circulation of gasses
o Gasses = co2 & oxygen o Didn't need this as much in aquatic plants - no/less air spaces - Instead used diffusion w/ dissolved gasses in the water o Mostly in the leaves
Human uses of cyanobacteria
o Pond scum for biofuels o Nostoc can be consumed o Some edible Cyanobacteria are the reason we exist!
Apical meristem
o Population (or one) undifferentiated cell(s) o Each cell undergoes mitotic divisions à two offspring cells (one of which is a meristem cell and the other goes of to become differentiated)
Chlorophyceae- Chlamydomonas
o Unique structures: - "pyrenoid" in chloroplast for starch synthesis - "eyespot" in chloroplast is a light sensing structure. don't like super bright like, helps avoid bright light so they can swim to dimmer light - flagella roots direct movement in response to light o Reproduction - + and - - use different pheromones to find each other - haplontic and isogamous
Liverwort Synapomorphy
oil bodies elaters
simple fruit
one like a cherry or apple
prothallial cell
one of the cells produced by the first division of the microspore in a gymnosperm and believed to be a vestige related to the fern prothallus
non cyclic electron flow (part of light reactions)
one of two possible routes of electron flow, enzyme splits H20 and uses the electron to replace those lost by chlorophyll (o2 is released)-goes through photosystem ONE and TWO!
double fertilization
one sperm fertilizes the egg/zygote (2N) one sperm combines with the 2n Polar nuclei=endosperm (3N)
seeds
only in angiosperms and gymnosperms embryo+food supply+protective coat are a solution to resisting harsh environmental conditions and dispersing offsprings if "..." isn't dispersed it would have to compete with family for resources
chloroplasts
organelle sorrounded by double membrane, in leaves so they can face sun and absorb light
branched sporophyte
orophytic axis=stem a supportive organ bearing reproductive organs or leaves; early vascular plants had dichotomous branching then subsequent plants formed pseudomonopodial branching;
Exarch
outside inward old xylem on the outside
monocots
parallel veins (orchids or lilies)
photosystem 1 ( COMES SECOND and part of light reaction!)
photon makes NADPH* (note: when cyclic cycle goes through this system it makes ATP only!)
noncyclic summary
photosytems 2 and 1, makes NADPH and ATP and releases O2
Stromatolites:
plant fossils - oldest fossils on earth (3.5 bya) o Widely accepted by scientists as one of the earliest forms of life o Composed of cyanobacteria
stomata
pores in leaf surface that open up and close up to regulate gas exchanges
bifacial vascular cambium
produces secondary xylem (wood) and secondary phloem
Plasmodesmata
protoplasmic connections established during phragmoplast formation between neighboring cells that allow rapid communication between cells
unequal dichotomous branching
pseudomonopodial growth Psilophyton
protostele
red = xylem blue = phloem
3 Mini Steps of Calvin Cycle: reduction #2
reduces 6 carbon molecule equal to G3P, NADPH is used to reduce it, G3P comes out to make sugar, one of these G3P must be used to regenerate rubisco
Motile Sperm
requires water to complete life cycle
Rhizomes
roots as we know them today probably evolved from ___
Synapomorphy: Rosette Proteins
rose-shaped complexes found in the plasma membrane that regulate the deposition of cellulose wall microfibrils
-heterospory -endospory (development of gpt inside spore wall) -unisexual gpts -ligules
selanginellales,isoetales,lepitoderales Synapomorphies
autotrophs
self feeders
flower parts
sepals, petals, stamens, carpels (STUDY PICTURE) ONLY IN ANGIOSPERMS!)
agregate fruit
simple flower with several carpels like blackberries, rasberries
Apical Meristem
small area composed of cells whose only function is to divide
fern rhizome
solenostele amphiphloic with leaf gap
1 diploid
sperm + egg (seeds have TWO)
photolysis
splitting H20
fusiform sporangia
sporangia are unbranched, but in at least the type species the axes seem to branch just under the sporangia
Sporangia-bearing stems
sporangiophores
Leaves that bear sporangia
sporophylls
moss lifecycle
sporophyte (2n) --> meiosis --> spores (n) --> gametophyte (n) --> antheridia / archegonia --> sperm / egg --> zygote (2n) --> young sporophyte
Antheridiophore
stalked structures (that look like umbrellas) of the gametophyte that bear the male gametangia, or antheridia.
cont. dimorphic:
sterile (l) and fertile shoots
Moss and Hornwart Synapomorphies
stomates in sporophyte, columella
Cyanobacteria structure
storage of carbohydrates in the form of glycogen - surrounded by cell wall and mucilaginous sheath - inside: plasma membrane w/ protoplast - ribosomes and photosynthetic membranes w/ thylakoids and phycobilisomes (pigment) found but no other organelles - gas vesicles - DNA but no nucleus - no flagella or cilia, but can move
Cuticle Delayed Meiosis Stoma
synapomorphies for the Embryophytes
Renalia
terminal, reniform sporangia dichotomous branching
the action spectrum
the "absorption" spectrum is the idea that some wavelengths absorbs better than others like white absorbs all colors vs. black
fern roots arise from?
the rhizome
why do leaves lose their green color?
they lose it because of a decrease in dayloight, chlorophyll is absorbed into trees and conserves to other pigments start to show in wintertime
pteridophytes
things like ferns, they do not have seeds! and they live in damp areas
where do light reactions happen?
thylakoid membrane
True branching vs. false branching in filamentous organisms
true branching = parallel to original filament false branching = bump formed on filament and branch grows out at and angle
vascular tissue
tubes to transport nutried and water (from roots to leaves). they are what make plants (bryophytes do not have these)
Thallus
type of plant body that isn't differentiated into roots, stems, and leaves
xylem
type of vascular tissue that is dead and transports water
phloem
type of vascular tissue that is living and transports sugar
Archegoniaphore
umbrella-like structures that contain archegonia
circinate vernation
uncoiling of leaf from base to apex
Basal Green Eukaryotes (plants) - Micromonas
unicellular ancestor of chlorophyceae? Sexual reprodution?
Polytomy:
unresolved node of three or more taxa - considered to be sister taxa
photoautotrophic
use light as a source for their own food
3 Mini Steps fo Calvin Cycle: regeneration #3
uses ATP to rearrange G3P to rubisco, allows cycle to continue, for synthesis of one G3P, uses 9 ATP and 6 NADPH, uses ATP for RuBP for next Co2
Cyclic
uses Photo1, ATP ONLY, no 02 release
calvin cycle
uses atp already made, carbon enters and leaves as CO2, uses ATP to make G3P, cycle occurs 3 times to produce one 1 G3P (a co2 is put in each time of the cycle!) NADPH, ATP and CO2 come in, G3P [Glucose], H2O, ADP, NADP+ comes out
hydroids
water conducting cells
lycopsida (rhizomes --> rhizomorph --> roots
when did roots start?
- loss of motile cells
zygnematales synapomorphies
How long ago did lycophytes split from the pterophyte seed plant clade
~425 million years ago
Why would paraphyletic groups be used?
§ Bacteria & Archea (Prokaryotes) taken as a paraphyletic group even though Eukaryotes should be a part if it was a monophyletic group
Paraphyletic Group:
· Consists of all the descendants of the last common ancestor of the group's members minus a small number of monophyletic groups of descendants, typically just one or two such groups. - Includes common ancestor but not all descendants