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Bio 242 Diversity of Life Semester Notes

by: Mary-elizabeth Notetaker

Bio 242 Diversity of Life Semester Notes Bio 242

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Mary-elizabeth Notetaker
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Diversity of Life
Dr. Alexander
Biology, Bio, BIO242, biology242, Alexander, UofL, UniversityofLouisville, diversityoflife
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Date Created: 05/04/16
• Diversity of Life • evolution=framework ‣ change in organisms over time ‣ common ancestry- hands down heritable characteristics ‣ changes in allele frequency in a gene pool over time ‣ adaptations- environmental specific • features that better assist an organism to live in its habitat • changes can mold a species to a particular environment ⿞mechanisms of evolution ‣ natural selection- differential survival & reproduction of members of a species,those with better traits survive and reproduce to pass on beneficial heritable traits • not a random process- acts upon characteristics that are already present • genetic drift- random changes in allele freq that have nothing to do genetic fitness • gene flow- introduction/movement of new alleles for the same characteristic or trait from one population to another ⿞~ mixing of populations ⿞ex) ladybugs w/ 3 spots on wings mix w/ ladybugs w/ 2 spots on their wings • mutations- random/spontaneous changes in DNA sequence for a particular gene • sexual reproduction- increases variation in changing combinations for different traits ⿞happens when genetic material is exchanged and rearranged • Speciation ⿞ancestral population- original population ⿞population splintering- population splits for one reason or another,two populations are formed from one,and members of each population do not interbreed ⿞gene flow inhibited- dont reproduce due to habitual isolation ⿞genetic divergence- each population experiences changes in its population due to the environment they are in ‣ living in different environments can cause different adaptations,which eventually can cause them to become 2 diff species ⿞reproductive isolation- can no longer interbreed due to mechanical/gametic isolation • extant population- population branched from the original population • how to make sense of organismal diversity ⿞taxonomy & classification ‣ linneaus- developed binomial naming format (genus(capitalized) followed by specific epithet of the animal[all italicized]) & ⿞universal system...can't use common names in science ⿞Domain- Kingdom- Phylum- Class- Order- Family- Genus- Species ‣ domains:bacteria,Archaea,Eukarya ⿞systematics- individuals that gather any type of information about a species to be used to classify an organism ⿞phylogeny- evolutionary history of an organism or taxon(group) ‣ goal:produce a correct evolutionary history ⿞cladistics- science that uses the information from systematics (data) in order to construct evolutionary history (relation of one species to another) ‣ "clade" --> includes common ancestor and all its descendants • starts with order,then breaks down into order,family,genus,and species from there • phylogenetic trees ⿞line on left represents the beginning/root of ancestral pop ⿞branch points represent divergence of the population before ‣ multiple branch points in each tree ‣ when there are three that come from one branch point,it forms a polytomy,which is an unresolved pattern of divergence ‣ when there are two on the right side from a branch,the two resulting taxons are called sister taxons ‣ when a taxon is branched directly from the ancestral population,it is called a basal taxon (outgroup) (helps root ancestry of other species) • Phylogeny ⿞natural system that reflects ‣ evolutionary relationships ‣ less emphasis on ranking ‣ common ancestry ‣ homologous characters- characteristics that are heritable and come from the common ancestor • can be ⿞morphological ⿞behavioral ⿞biochemical ⿞molecular ‣ proteins (AA sequences) ‣ nucleotide sequences ⿞analogous character- homoplasis- are unacceptable in phylogenies ‣ develop from convergent evolution- similar traits develop in unrelated organism that live in similar environments due to independent events ⿞difficulties w/ phylogenetic relationships ‣ recognizing • homologies • analogies (homoplasies) • evolutionary reversals- revert back to an earlier adaptation in the lineage,like regressing to leglessness after developing them ⿞can look at it on the dna level ‣ sequence changes can change parts of the sequence,while part of it remains the same ‣ computer programs exist that can find homologies in dna sequences • can insert blanks into sequences where insertions/deletions may have occured to show the homology between the 2 or more sequences • linking classification & phylogeny ⿞done by forming clades...true clades: ‣ using common ancestry ‣ monophyletic- single common ancestor and all its descendants • can tell if it is one bc only need one snip ‣ can be referred to as hypothesis because it is subject to change • ex) new genetic evidence has comlpetely changed the idea of the first species to branch from single celled organisms...sponges no longer first ⿞paraphyletic grouping- not true clade... ‣ old group that is no longer valid ‣ includes some but not all the descendants ‣ needs more than one snip • ex) birds must be included in reptile order ⿞polyphyletic grouping ‣ grouping of organisms that have no common ancestor ‣ ex) not all insect eating plants have a common ancestor • Which characters are appropriate to consider when making monophyletic groups? ⿞homologies ⿞symplesiomorphy(shared by 2 or more groups) (plesiomorphy-ancestral state) ‣ shared ancestral character ‣ originated in ancestor of taxon ⿞synapomorphy(shared by 2 or more groups) (apomorphy-defines a clade) ‣ shared derived character ‣ not found in ancestors ‣ defines a clade ⿞parsimony ‣ simplest explanation ‣ best hypothesis • best fits data • makes fewest assumptions ‣ fewest homoplasies,especially if complex • analogous features • convergent evolution • horizontal gene transfer • vertical gene transfer Prokaryotes:Domains Bacteria &Archaea (ch 24) ⿞small ⿞pervasive (can live almost anywhere on Earth..espArchaea) ⿞versatile (represent every type of metabolic pathway) ⿞essential (responsible for changing out atmosphere from co2 to o2..cycle nitrogen[needed for macromolecules...nucleic acids & proteins]) • General prokaryotic Characteristics ⿞unicellular ⿞no membrane bound organelles ⿞no nucleus- have "nucleoid region" ⿞no cytoskeleton ⿞reproduce by binary fission ⿞smaller ribosomes • most common prokaryotic shapes ⿞cocci- round ⿞bacilli- rod ⿞spirochetes- spaghetti like • cell wall ⿞protects & maintains shape ⿞bacterial:peptidoglycan ‣ gram positive- thick peptidoglycan layer ‣ gram negative- thin peptidoglycan layer with another membrane over top ⿞archael:other polysaccharides & proteins (no peptidoglycan) • cell surface structures ⿞capsule- external to cell wall.."hairy" layer ‣ formed of polysaccharide linked layers...sticky ‣ protective layer..can make it stick to host better(enhances pathogeny) ⿞fimbriae- protenatious tubes that stick out from cell surface ‣ enhance adhesive ability ⿞flagella- structure used for motility ‣ diff types developed independently • prokaryotes lack internal compartments ⿞but still carry out necessary processes ⿞some can make endospores- compacted genetic material surrounded with tough structure very resistant to attack • genomic organization ⿞single circular chromosome in nucleoid region ‣ not associated with histones,but there are other organizing proteins ⿞plasmids...carry continuancy genes..can offer antibiotic resistance...can be transferred from 1 species to another • reproduction ⿞binary fission ⿞origin of replication- where chromosome is duplicated ⿞cell wall is formed after information is duplicated ‣ cell wall begins to pinch in and informations splits into 2 cells • prokaryotic genetic diversity ⿞rapid reproduction ⿞mutation ⿞genetic recombination ⿞horizontal gene transfer ‣ transformation- can pick up foreign dna from dead cells ‣ transduction- when bacteriophages infect diff bacteria they transfer bacterial dna from one bacteria to another ‣ conjugation- when 2 bacteria get close enough they can exchange dna as hey approach each other • sex pilus allows this to happen (like a fimbrea) • nutritional and metabolic modes ⿞energy source ‣ phototrophs:light • lights,co2 ‣ chemotrophs:organic or inorganic molecules • chemoheterotrophs:need organic carbon • chemoautotrophs:can oxidize inorganic compounds and get energy from them • photoheterotrophs:light,organic compunds ⿞carbon source ‣ autotrophs:co2 ‣ heterotrophs:organic mols • metabolic relationships to oxygen ⿞obligate aerobes.. use o2 ⿞faculative anaerobes..use anything available ⿞oblagate anaerobes...poisoned by o2 • nitrogen metabolism ⿞nitrogen fixation ‣ convert n2 to nh3...can only be done by bacteria ⿞nitrification- conversion of nh3 to no2- and no3- • bacterial clades ⿞proteobacteria-gram-,form transfer to anima ⿞chlamydias- usually pathogenic?,gram- ⿞spirchetes- spiral shape,gram- ⿞gram+ bacteria- endospore formation ⿞cyanobacteria - imp in generation of chloroplasts • Archaea ("sister to Eukaryotes"..but morphologically similar to prok) ‣ shapes- have multiple diff ‣ first came from extreme environments ‣ also found in mild environments ‣ most ecologically diverse ‣ no pathogenic form ➡Make comparison lists btwn prok,archaea,and euk⬅ ➡ see picture⬅ ⿞thermophiles- can survive at very extreme(high) temps ⿞halophiles- can survive in high salinity environments ⿞methanogens- combine c w/ h gas to form methane,which also produces energy (unique to archaea) ‣ anaerobic...poisoned by o2 ‣ usually found in swmapy,deep sea hydrothermal vents,or gastointestinal tracts of various organisms ⿞acidophiles- can live in very acidic environments ⿞psychrophiles- can live in extremely cold environments • Roles of prok(importance) ⿞nutrient cycling in ecosystems ⿞nitrogen fixation ‣ also convert things like N,S into organic mols ⿞symbioses- w/ humans,cows,etc breaking down foodstuffs ‣ prok & plant...assist in N fixation ‣ prok & fungi- lichens..can help w/ ecological succession ⿞could be pathogens.....small fraction ⿞bioremediation- cleaning up oil spills and things of that nature ⿞genetic engineering- put genetic instructions into them to get them to produce substances needed for other species,such as human Chapter 25:Origin & diversification of eukaryotes • evolution of euk cells & multicellularity • Domain Eukarya ⿞KingdomsAnimalia,Planta,Fungi,and various "protist" kingdoms • currently organized into 4 supergroups (clades) of euk organisms • phylogeny in dynamic state (can change) ⿞includes all multicellular organisms except the large ones (animals,plants, fungi) ⿞archaeplastida,stramenopiles (part of SAR groups),opisthokonts <-- important groups • evolution of euk(means true nucleus) cells ⿞prok are ancestors ⿞~3.5 bil yrs ago-1.8 bil yrs ago (fossil evidence) ‣ gradual process ⿞organisms we're familiar with have developed since about 600 million yrs ago • endosymbiosis theory- 1 organism living in another ⿞engulfed aerobic bacteria..allowed more efficiency of energy ‣ probably the ancestor of cyanobacteria ‣ heterotrophic euk w/ mitochondria preceded development of photosynthetic euk w/chloroplasts ➡see picture⬅ • origins of multicellularity ⿞colonial forms- groups/clusters of same types of cells that are held together ⿞how are cells held together? ‣ ECM • shared cell walls • connecting proteins ⿞true multcellularity ‣ likely happened in multiple indep events ‣ red,green,and brown algae ‣ plants,animals,fungi • volvox seems to be first ⿞rearrangement and coopting of existing genes ⿞Dna sequence data support that choanoflagellates are ~sister to all animals • evolution of animal multicellularity ⿞chaonoflagellates ‣ morphological homologies ‣ dna seq homologies ⿞homologous protein domains ‣ cell adhesion proteins • cadherin ⿞large family of ECM proteins ‣ cell to cell signaling ⿞comparison showed that choanoflagellate cadherin-like protein & animal cadherin domains .....dont need lots of genetic changes ~~~~ chapter 10 • life cycle diversity ⿞asexual- simple..produces clones...rep of dna then cell splitting ⿞sexual- exchange/recombination of genetic info from 2 diff individuals ‣ gametic life cycle ‣ zygotic life cycle...multicellular haploid individual...mitosis produces gametes in these individuals (fungi)...zygote is only representative of diploid state in fungi,then meiosis occurs to produce fungal elements(sexual spores) ‣ sporic life cycle...diploid form is sporophyte..plants and some algae... alternation of multicellular generations...fertilization produces zygote, mitosis produces haploid gametophyte... • mitosis/meiosis...diploid/haploid..etc • terms for sexual lifecycles ⿞spores ⿞gametes ⿞gametic life cycle ⿞zygotic llife cycle ⿞sporic life cycle ‣ sporophyte ‣ gametophyte ‣ heteromorphic(diff) or ospmorphic(look same) -brown algae are in SAR clade -all subgroups inArchaeplastida • pg in ch 25..evidence supporting endosymbiont theory..(look up) ⿞own dna ⿞own membrane (dbl membrane) ⿞ribosomes ⿞make own proteins • do study questions on bb • create timeline for evolution of diff organisms ⿞earth..4.5 bil yrs ago ⿞ ago ⿞life..3.5bil yrs ⿞1st euk fossil evidence..1.8 bil yrs ⿞euk multicellular organisms..1.2 bil ⿞multicellular colonial euk..800 mil ⿞large multicellular euk...600 mil ⿞land animals start to develop...470 mil...plant/fungi like organisms preceded animals on land • charophytes- brown algae • chlorophytes- green algae • SAR-stramenopiles(placement of flagella)- brown algae ⿞characteristics: ‣ chlorophyll a(allows organisms to undergoe photosynth that releases o2 after splitting water..absorbs red & blue pigments) & c(absorbance slightly diff than a..absorbs light chlorophyll a cant) ‣ carotenoids (fucoxanthin...yellowish-brownish pigment..allows absorption of wavelengths diff than a & c) ‣ laminarin- defines carbohydrate (instead of starch in land plants) ‣ cell wall contains.. • cellulose- common • alginic acid- clade definer ‣ largest type of algae ‣ parts..exs: • blades..leaf like..photosynth • stipe...stem and getting it closer to light • holdfast...attached to stipe..secretes enzyme that attaches them firmly to whatever they're on ‣ ...kelps(giant seaweeds)..very in deep parts of ocean ‣ heteromorphic alternation of generations(look diff)..diploid sporophyte is main stage..give rise to sexual flagellated haploid spores by meiois...produces gametes by mitosis • Archaeplastida ⿞red algae- ‣ chlorophylls a & d ‣ contain phycoerythrin- red pigment...overpowers chlorophyll presence...can exist in very deep waters (absorbs blue wavelengths..which penetrate farthest into water) ‣ floridean starch & mannitol ‣ cell wall: • cellulose • agar..can be used to culture microorganisms • carageenan..used in processed foods to suspend things ⿞green algae ‣ chlorophylls a & b ‣ carotenoids (carotene & xanthyophyll...absorb blue & green pigments) ‣ call wall:cellulose ‣ starch ‣ alternations of isomorphic generations(look same) (celetic?)..variation of sporic life cycle...sporophyte is diploid..some cells in sporophyte undergo meiosis and grew mitotically to produce haploid gametophytes(which look morphologically identical to sporophyte).. gametes fuse to produce zygote,which divides mitotically to give rise to new sporophyte generation • green algae and land plant similarities ⿞photosynthetic,chl a,chl b,carotenoids ⿞euk & multicellular autotrophs ⿞cellulose in cell walls;starch for storage ⿞reproduction ‣ plants:sporic meiosis only ‣ algae:all forms of meiosis observed ⿞reproductive structures ‣ complex multicellular organs in plants (special organs producing spores or gametes) ‣ simpler structures in algae Chapter 26 • Adaptation of plants to land • relationships among multicellular euks ⿞fungi & animals are sisters ⿞charophyte algae(special subgroup of green algae) and land plants(~embryophytes) are sisters ⿞algae is a paraphyletic grouping • charophyte algae (closest algal relatives of plants...sister taxa) ⿞homologies w/land plants ‣ rosette complexes in the plasma membrane..small cirlce completes that help link the glucose to form cellulose (linear in other algae) ‣ sperm ultrastructure- placement of centrioles,flagellum,etc ‣ nuclear & chloroplast genes....many homologies ‣ sporopollenin- protective polymer...helps prevent spores and pollen from drying out • covers zygotes of charophytes • covers spores and pollen of plants ⿞plant traits not in charophyte algae ‣ apical meristems...clusters of actively dividing cells that allow growth and organ formation..usually found at the tips of organs (ex,roots) ‣ sporangia that produce spores (always..always heteromorphic) • protected with sporopollenin ‣ multicellular embryos(formed by mitotic divisions...develops after a zygote) • dependent on gametophyte tissues • land plants are embryophytes • transition from aquatic to terrestrial (land) environments ⿞problems ‣ support ‣ decication (drying out) ‣ mineral acquisition ⿞solutions ‣ cuticle (waxy cutin...covers parts that touch air,reduces water loss) ‣ roots..anchorage,storage,transport of necessary substances ‣ photosynthetic leaves to root system ‣ leaves- large surface area for photosynth...gas exchange • stomates...allow entry of co2 and h20,can open close,prevent dehydration ‣ vascular tissues..aid in movement • xylem- absorbs water and dissolved minerals ⿞ligin- strengthens cell walls that make up xylem • phloem- moves carbohydrates • Plant groupings ⿞byrophytes/non-vascular plants(cant transfer fluid inside) (470 mil yes ago) • exs:liverworts,mosses,hornworts ‣ "amphibia of plant kingdom"...very small,very dependent on water ‣ "carpet" forming... • thalloid or leafy..not real leaves • rhizoids..anchoring structures..very small ‣ sporic meiosis- alternation of generations • gametophyte (haploid) is main plain phase seen (larger than sporophyte) ‣ adaptations to land • stomates ‣ lifecycle of moss: • male produces sperm(need water) and swim to female gametophyte (has egg..archegonia..produce egg) anthroidia produce sperm.zygote undergoes mitotic divisions,and sporangium grows on top of gametophyte.haploid spores released and produce next gametophyte generation ⿞gametophyte - haploid ‣ larger and more persistent ⿞archegonia- contain an egg (haploid)..where sporophyte grows ⿞antheridia- produce swimming sperm(...gametophyte) ⿞fertilization happens in archegonia,but requires water ⿞goes thru mitotic divisions to produce a sporophyte(haploid) that is dependent on the gametophyte ⿞sporangia undergo mitosis to produce haploid spores (ephermeral generation..short lasting) • seedless vascular plants (425 mil) • ex) lycophyta(includes lower plants,but those higher than mosses ex: club moss contain conelike clusters that produce spores), monilophytes(ferm like...ex:ferns) ‣ increasing height ‣ vascular system ‣ lignin- polymer supporting cell walls,allows transport of nutrients ‣ true leaves,stems,and roots ‣ cuticle- waxy sub covering plant,prevents h2o loss ‣ stomates- pores that can open and close ⿞likely selected for due to ability to grow more vertically ⿞life cycle changes:...still sporic • larger,conspicuous sporophytes (2n) ⿞independent • smaller gametophyte (n) ⿞independent but ephemeral ‣ rhizome (underground stem that anchors fern frawns)...grow to form leaf like stx (sporophyte),sporangia undergo meiosis to produce haploid cells,sporangia cluster to form sorus(es),diploid cells in sporangia undergo meiosis to produce haploid spores,spores grow germinate into haploid gametophyte,archegonia and antheridia grow on gametophyte, gametophytes undergo mitosis,producing archegonia that have eggs,and antheridia form flagellated sperm,meet water,fertilization happens in archegonia,forming zygote that grows into new sporophyte ‣ fern life cycle: • sporophyte (2n) • fiddlehead-frond • rhizome • sporangia- produce spores ⿞special cells undergo meiosis to produce haploid cells-> spores (n) • haploid spore germinates into haploid gametophyte • gametophyte produces archegonia(w/eggs) and antheridia(w/sperm) • zygote produced(2n) that forms into sporophyte ⿞leaf evolution ‣ flat blades increase surface area ‣ two types of leaves: • microphylls- leaves w/single vein ⿞410 mya ⿞lycophyta(seedless vascular) • megaphylls- leaves with a highly branched vascular system (all newer plants) ⿞370 mil yrs ago ⿞monilohytes & seed plants • seed plants (305 mil) ‣ oldest fossils:360 mya ‣ earliest gymnosperm(cones) fossils:307 mya ‣ earliest angiosperm(flowes) fossils:140 mya ⿞see diagram in pp ⿞reproductive adaptations of seed plants: ‣ greatly reduced gametophytes • develop on sporophyte generation ⿞megasporangia(ovule) ⿞microsporangia(pollen) ‣ ovules- female stx formed and retained on sporophyte..protects developing gametophytes and sporophytes ‣ pollen- immature male gametophyte.released for sexual reproduction ‣ seeds- can distribute next generation to another area in a protected stx • advantages: ⿞protection ⿞prevents desiccation ⿞dormancy ⿞aids dispersal • gymnosperms ("naked seed") ⿞released from parents w/out any casing other than seed coat ⿞sexual stxs are in cones/spikes layered with "scales" ‣ at bottom of megasporangia is ovule ‣ at bottom of male cone(microsporangia) is sporangium containing diploid cells that will undergo meiosis ⿞ovule development ‣ female cones- all tissues are 2n ‣ start small & grow large and woody • 1 to 2 yrs for seed development ‣ ovules located at base of cone scales • integument(2n)- forms seed coat • megasporangium (2n) • megasporocyte (2n) ‣ within the megasporangium (2n)..1 megasporocyte (2n) undergoes meiosis • 4 haploid cells produced,but 3 degenerate • net production:1 functional megaspore(n) grows by mitotic divisions into a gametophyte (still inside megasporangium) producing a female gametophyte w/ 1 or 2 archegonia ⿞gymnosperm pollen development ‣ male cones are papery and ephemeral ‣ microsporangia(2n) are sacs with diploid cells located at base of cone scales • each microsporophyte (2n) undergo meoiosis ⿞4 microspores (n) ⿞each divide mitotically and gives rise to pollen grains,sprotected by sporopollenin • pollen grains are released from parent sporophyte cones ⿞immature male gametophyte ⿞dispersed by wind ⿞generative cell(divides once by mitosis and gives rise to 2 sperm nuclei) & tube cell(grows cellular stx into archegonia where egg is) ‣ pollenation- delivery of male gametophyte to receptive stx • not equivalent to fertilization • pollen grains sift through open scales of small female cones • fertilization takes place after pollination ‣ pollen grain germination:tube cell grows into pollen tube and grows through female gametophyte and into the ovule ‣ next,generative cells does through meiosis and one sperm moves into archegonium to egg ⿞seed development in gymnosperms ‣ integument-> seed coat (2n) ‣ female gametophyte (nutritive tissue)(2n) ‣ embryo (2n) ⿞reproductive synapomorphies • ovule ‣ contains a greatly reduced female gametophyte ‣ provides stx for seed formation • pollen ‣ greatly reduced male gametophyte • dispersed by wind/air ⿞sperm- haploid nucleus • fertilization does not require water • seeds pine life pp • Angisperms (140mya) (most successful plant group) ⿞reproductive synapomorphies ‣ further reduction in gametophytes ‣ shortened seed development time ‣ flower ( cluster of modified leaves that protect embryo) • coevolution with pollinators • attract and reward pollinators • double fertilization- seeds with triploid (3n) endosperm • fruit- coevolution w/ seed dispersers ⿞enhances seed dispersal • flower parts...table on pp ⿞anther is microsporangium ⿞carpel is landing place for pollen ⿞pollen development ‣ anther(2n) is 4 fused microsporangia ‣ microsporophytes (n) ‣ get 4 microspores from meiosis fro microsporophytes ‣ 2 celled pollen grain(n) = male gametophyte • tube cell (n) • generative cell (n)- divides mitotically to produce 2 sperm nuclei • all protected by sporopollenin ⿞ovule development in ovary/carpel ‣ ovule= integument,megasporangium,megasporocyte (2n) ‣ megasporocyte-> meoisis ‣ 4 haploid cells,3 degenerate ‣ 1 functional megaspore (n) -> 3 mitotic divisions ‣ female gametophyte = 8 called embryo sac • 3 antipodal cells • 2 polar nuclei in central cell • 2 synergids • 1 egg ⿞pollination & dbl fertilization ‣ transfer of cell grown down carpel and forms pollen tube ‣ generative cell(n)-> 2 sperm nuclei ‣ dbl fertilization • sperm + egg= zygote • sperm + 2 polar nuclei - triploid endosperm (3n) serves as food source for sporophyte when seed germinates ⿞post fertilization in angiosperms ‣ ovules develop into seeds • integument --> seed coat • zygote --> embryo • endosperm--> nutritive tissue ‣ carpel(ovary) develops into fruit to aid in seed dispersal • ovary wall develops into pericarp ⿞diff ways angisperms have exploited to disperse seeds ‣ water- coconuts..endosperm and endocarp inside buoyant husk ‣ wind- winged/plumed ‣ animal- b abiotic- doesnt require organisms to spread pollen biotic- requires organisms " " " Test:chs.20,24,25,26,30(597-607) Chapter 26 • Fungi ⿞break down organic matter ‣ nutrient cycling ⿞essential for plant nutrition ⿞symbioses ‣ pathogenic ‣ beneficial • fungi characteristics ⿞eukaryotic ⿞haploid (diploid stage is very brief..then creates haploid spores) ⿞heterotrophic (chemoheterotrophs..need fixed carbon) ‣ absorptive- release enzymes that allow them to break down chemicals that are very hard to break down(live in their food) ‣ produce exoenzymes • extracellular digestion,then absorb the monomers • nutritional modes ⿞saprobes- decompose and live in dead plants & animals ⿞parasites- pathogenic to living plants and animals ⿞mutualistic symbionts- have fair trade w/ other organism ‣ mycorrhizae ‣ lichens • body structure ⿞mushroom cap- where sexual spores are produced ⿞unicellular- yeasts ⿞multicellular filaments ‣ underground or visible on surface (mold) ‣ hypha (hyphae) • types: ⿞septate- have small holes,each cell has single haploid it grows,nuclus divides and moves to growing tip,then cell wall forms btwn the newly made cells (derived feature) ⿞non-septate- ancestral feature...numerous haploid nuclei that are genetically identical..cells not separated by cell way..senositic? ⿞haustoria- hypofilament makes projections into adjacent cells of another organism...makes hole in cell wall (of plant) and send a hyphae through it,and is there but does not hurt it ‣ mycelia- mass of hyphae ⿞glycogen- storage carbohydrate (like animals) ⿞chitin- in cell walls • reproduction ⿞asexually ‣ conidia- spores...can be formed in many ways... • tips of branches pinch off into spores ‣ budding- nuclei divide asymmetrically...cytoplasm divides (also asymm).. progeny are small,parent is bigger. ⿞sexual ‣ zygotic meiosis (lc)- haploid individual • secrete pheromones..two diff types(but same species) grow towards each other and grow together.. ‣ plasmogamy- hyphae(cytoplasm) fuse together ‣ heterokaryon- "different nuclei"..two diff types of nuclei uniting in same individual ‣ karyogamy- "nucleus marriage"..equivalent to fertilization..nuclei are the gametes..fuse to form zygote..goes thru meiosis and produced sexual spores ‣ spores..give rise to new fungal organisms • generalized fungal life cycle (on 26 PP) • 5 diff groups ⿞chytrids (basal group) ‣ in lakes and soils ‣ cell wall w/ chitin ‣ have flagellated spores (zoospores) ⿞zygomycetes ‣ non-septate hyphae ‣ zygosporangia (fruiting body) (sexual spores) ‣ exs: • rhizopus stolonifer (black bread mold) • pilobolus ⿞glomeromycetes ‣ non-septate hyphae ‣ arbuscular endomycorrhizae (most common form of mycorrhizae relationships) • positive symbiotic relationships w/ plant roots (haustoria) • look like little trees • live inside plant cells ⿞gets fixed C and water from the plant ⿞plant gets enhanced ability to take up nutrients (specifically P) ‣ enhances the surface area for nutrient uptake for plant and fungus ⿞ascomycetes ‣ septate hyphae ‣ complex sexual structures...produce elaborate fruiting bodies • ascocarp- fruiting body of ascomycetes ⿞ascospores...result of meiosis ‣ exs:fungi w/ mushroom/cuplike stxs/truffles ⿞basidiomycetes(most derived fungal group) ‣ septate hyphae ‣ some species are ectomycorrhizae (form a sheath of mycelia around root tips)..usually seen with tree roots ‣ complex sexual stxs • basidiocarps- fruiting body...produces basidiospores from meiosis • basidia(clublike stx) forms with gills...contains basidia.. karyogamy(fertilzation) occurs in basidia...basidiospores form in "gills", then get dispersed..get 4 spores from each basidia ‣ exs:toad stool,shelf fungi,puffballs • dikaryotic- two haploid nuclei ..but still heterokaryon • lichens- beneficial symbiotic relationship ⿞symbiosis ⿞grow on rock,bark,burned forests,lava flows<-- help break down to make microenvironment for other microorganisms to live ⿞exs:fruticose,crustose,foliose ‣ low lying,flat,crusty looking ‣ various levels of pigment ⿞components: ‣ fungal member (hyphae network)(ascomycete or basidiomycete) (gets fixed carbon) • provides physical environment ⿞gas exchange ⿞retention of h2o & minerals ⿞secretion of acids ‣ photosynthetic alga(provide fixed C) or cyanobacteria (provide fixed C & N) • occupy an inner layer below the fungal surface (gets nice area) - look at notes on paper (missed day) • Secondary Root Growth(occurs simultaneously w/ primary growth) ⿞vascular cambium(1st lateral meristem,gives rise to other elements)= one continuous cylinder ⿞formation ‣ between 1st xylem and 1st phloem of vascular bundle ‣ ground tissue btwn vascular bundles ⿞secondary growth xylem(dead cells w/ almost no cross walls) to the inside ‣ wood ⿞secondary growth phloem(living cells,have partially digested cross walls so photosynthate can move relatively fast through them) to the outside ‣ crushed at the end of the season(still there,but layer forms on inside of old layer(towards middle part of phloem) ?- where can you find the youngest parts of a tree? in primary growth- in tips of roots and shoots(length) (develops from apical meristems) in secondary growth,is whats adjacent to the vascular cambium (width) closest to the outside(secondary xylem) (vascular cambium grows and generates cells that differentiate into various types) • cork cambium= bark(consists of anything external to vascular, secondary phloem,cortex,cork cambium,cork(so..phloem and periderm) (periderm helps make up bark) (forms from original cortex surrounding vascular tissue..differentiates into cambium cells,producing cork cells to the outside and another cortex layer to the inside)...dead at maturity.. suberin(waxy,protective) allow for protection of enlarging tree trunk. • middle...oldlest part of tree..wood darken..almost nonfunctional • sapwood..inside tree but outside heartwood..still somewhat functional • Secondary growth:periderm- cork cambium and cortex • cork cambium ⿞cortex derivite(parychyma cells differentiate to form meristematic cells) • cork cells to the outside ⿞sclerenchyma ⿞secondary cell walls with waxy suberin • phelloderm (parenchyma cells) to the inside • early spring wood has very large diameters...wide diameter conducting elements (trachea and vessels) • late summer wood...smaller diameters • bark- all tissus external to the vascular cambium ⿞secondary phloem ⿞periderm ‣ cork,cork cambium,phelloderm,secondary phloem (if any) • lenticels- gas exchange ⿞birch tree types ‣ slits in trees,apples,loosely packed cork cells ("nodes") on trees • girdling a tree ⿞can happen naturally or intentionally ⿞peeling bark off in a complete layer around an entire section of the tree (in a circle).....destroys the phloem and vascular cambium Chapter 29 • roots need oxygen (through roots and lenticels on tree) ⿞produces co2,which leaves roots • h20 and minerals travel up roots to regions of primary growth and goes up and out through leaf pores • water and organic mols moves in phloem • water and inorganic mols move in xylem (vascular tissue) • short distance transport- across cell membranes • bulk flow- movement of things across membranes in response to pressures • plasmodesmata- small dissolved perforations in cell walls,allows cytoplasm and plasma membrane to be connected from cell to cell • plant transport routes ⿞apoplastic route- travels through apoplast (cell wall..doesnt cross membranes) ⿞symplastic route- travels through cytosol of cells (connected by plasmodesmata) must pass throgh some membranes ⿞transmembrane route- crosses cell membrane,into apoplast,then into symplast,repeat • compartments ⿞apoplast- cell walls and dead material ⿞symplast- continuum of cytoplasm • solute and water transport in plants ⿞long distance tranport ‣ bulk flow ‣ requires pressure gradient • xylem under plus force • phloem under negative force ⿞short disance transport...across cell membranes ‣ active transport- needs atp...moves from [lower] to [higher]...allows cell to maintain uneven concentrations ‣ passive transport- doesnt need atp...solute/water moving down concentration membrane • simple diffusion- solute/water moves down [ ] gradient..dsnt need special protein carriers...slide through phospholipid bilayer • facilitated diffusion- special specific proteins that transport certain ions down [ ] gradient • osmosis • protons pumped to outside of cell so ph is lower ⿞creates energy gradients: ‣ membrane potential...other cells can bring solutes in up their [ ] gradient from proton pump(cotransporters and ion channels) ‣ proton gradient • osmosis- diffusion of water down its [ ] gradient,across a semi-permeable membrane...always passive ⿞water moves from a region of low solute concentration to a region of high solute concentration,...but still moving down its own [gradient] ⿞aquaporins- special protein facilitated diffusion molecules..allow plant and other cells to more closely control how much water moves by osmosis • water potential- psi ...measure of potential energy of water ⿞expressed in pressure units,MPa ⿞plant cell 0.5 MPa...has positive water potential bc of cell wall and pressure pushing out ⿞car tire 0.25 MPa ⿞home plumbing 0.5 MPa ⿞factors affecting water potential: ‣ pure water at normal pressure has 0 MPa ‣ solutes component- affect in a particular compartment ‣ pressure component ‣ pressure for each compartment • • solute addition decreases (-) • positive pressure increases (+) • negative pressure decreases (suction or tension) (-) ‣ high to low ‣ equilibrium ....water will stop moving when [ ]s are equal • must consider magnitude and sign of ‣ physical pressure increases ⿞animal cells outside the cell ⿞plant cells...turgor pressure ‣ rigid cell wall prevents expanision ‣ plant cell (inside) < environment (outside) • water moves into cell • internal hydrostatic pressure directed outward ⿞walled vs.unwalled cells ‣ figured 5.11 in book....or look in ch 29 slide • hypotonic ⿞ in < out • isotonic ⿞ in = out • hyertonic ⿞ in > out • movement of xylem sap ⿞short distance transport ‣ osmosis,active & passive transport of cell membranes ‣ happens in root cells,cortex,endodermis (forces solutes and water to move through cell membranes if they havent already done so) ⿞long distance transport ‣ bulk flow(pressure generates and tension is generated) ‣ happens in vessel elements and tracheids ⿞casperian strip...suberized layer of endodermal cell..along radial and transverse cell walls...what forces things through cell membranes and doesnt let them continue to go through apoplast • endodermis- selective sentry ⿞intermost layer of cells in the root cortex ⿞surrounds the vascular cylinder ⿞casperian strip,suberin ‣ blocks apoplastic pathway • ascent of water and minerals up xylem (from root tips up to top of tree and out leaves) ⿞root pressure...minor push force... ‣ mineral ions pumped into root xylem • soil > root ⿞water flows in osmotically ⿞goes in thru cortex and into stele and vascular elements..increase in pressure causes upward push(pos pressure) of xylem sap ⿞cohesion-tension hypothesis:pulls water up by force... ‣ transpiration- evaporation of h2o from the stomates (must be let water evaporate and to take in co2) ‣ water evaporates from leaf spaces...spongy mesophyll(air spaces...musty)...remaining water coats the surfaces of the cells...begin to pull on each other in a chain like manner ⿞tension develops at air-water interface • transmission of pull force ⿞cohesion(stick to themselves) & adhesion(stick to hydrophilic subs...tubules) of h2o ‣ helps water to move against gravity continuously ⿞water brought to leaf mesophyll thru veins(have xylem and phloem) ⿞adhesion to cellulose microfibrils ⿞cohesion of water to itself ⿞hydrogen bonding- give high tensile strength...allows long unbroken pillars of water ⿞water potential steadily decreases as you go up from the bottom • transpiration regulated by stomata ⿞plant controls water loss by stomates(mostly on bottom of leaf)- made of 2 guard cells located on bottom of leaf...adaptation to limit evaporation/ transpiration ‣ stomatal apparatus- stomata and 2 guard cells ⿞opening- guard cells swell(increase turgor pressure),causing a bowing out of the cells,leaving a hole in the middle of the two ⿞closing- guard cells shrink (decrease turgor pressure) ⿞guard cells...have primary cell wall... ‣ inner walls are very thick ‣ outer walls are thinner ‣ cellulose microfibrils wrap around guard cell radially • cause guard cells to bow outward when they swell...potassium ions fill • opp when shrinking...potassium ions leave • blue light receptor- special protein in membrane that recieves blue light and starts signal trasduction pathway that starts pumping potassium ions into the cell,creating a membrane potential • transpiration affected by environment ⿞light ⿞co2... ‣ high levels:stomates tend to close bc getting enough co2 ‣ low levels:stomates tend to open bc not getting enough co22 ⿞circadian rhythm ⿞temperature... ‣ excessive heat:stomates close...high temp increases evaporation..limits water loss ⿞water status- trumps all other factors ‣ dehydrated:produces absizic acid...moves to leaves causing stomates to close...decreased photosynthetic rates • adaptations to limit water loss ⿞cacti(reduced leaves...spines) ⿞hairs(reflect sunlight) ⿞recessed stomates...sunk in pits...further limits evaporation • translocation in phloem (mostly in herbacious plants) ⿞transport of phloem sap- water with dissolved sucrose and other organic nutrients ‣ moves from sucrose source(producer) to sucrose sink (consumer) • can change depending on season and developmental stage of plant ⿞ex) leaves start out as sinks,then become sources when they are photosynthetic,then go back to sinks as they prepare to fall off for winter ‣ sucrose.. • can be active or passive transport from mesophyll cells to get it into sieve tube elements[devoid of certain elements...loaded w/sugar and sap) (can be helped by adjacent companion cells) • passive transport out of phloem • h+ gradient helps move sucrose ⿞require adjacent xylem elements ‣ provides water ‣ creates pressure head(pos pressure) ⿞bulk flow ‣ high pressure --> low pressure ⿞pressure flow hypothesis- phloem loads at source,then when it reaches the sink cells,it moves into cells by passive transport ‣ sucrose actively transported into sieve tube element,which decreases water potential ‣ water from adjacent xylem moves into sieve tube element,creating a positive pressure...then sap moves towards sink ‣ sucrose unloaded at sink,water potential at that part of sieve tube element decreases and the water recycles back into the adjacent xylem Chapter 28 - plant nutrition • most of plant comes from the air(co2),not the soil. • most of plant is water,but most of dry part of plant is organic mols • soils ⿞topsoil ‣ parts... • particulates derived from rock ⿞sand(largest),silt(middle),clay(smallest particles,hold water tightly) ⿞loamy soils are best..have = proportions of all 3 • humus...dead organic decaying material ⿞slow release of nutrients,nitrogen,phosphorus, well as air spaces • living organisms...esp bacteria(prep soil for plant roots),archaea,fungi, mycorrhizae,cyanobacteria(upper levels),protists,various invertebrates(esp.nematode airate soil) • air spaces ⿞soil particles are negatively charged,surrounded by water ‣ when root around: • root hairs surrounded by lower pH...releases H+ ions ⿞also H+ ions from proton pump(usesd to actively bring in other ions)...enables cotransport of ions ⿞h+ ions imp in cation exchange- pos ions(calcium,potassium, sodium) that adhere to neg soil particles... ‣ soil particle will exchange h+ with pos charged ion • mineral uptake by roons ⿞anions- neg charged ions...cant bind to soil particles ‣ imp:phosphate(po4,3-),nitrate(no3-),sulfate(so4,2-) ‣ organic mols better used in fertilizing soil ⿞cations- made available to roots by H+ exchange ‣ K,Ca,Mg • essential elements9table 29.1) ⿞macronutrients- c,h,o,n,p,k,Ca,Mg,s ‣ proteins,nucleic acids,chlorophyll ‣ needed for plants to complete life cycle ⿞micronutrients ‣ fe,cl,cu,mn,zn,mo,b • nitrogen fixation- conversion of n2 to nh3 ⿞only done by bacteria ‣ ex) rhizobium,frankia,klebsiella ⿞nitrogenase....helps break n bonds ‣ inhibited by oxygen...why it happens in soil • plant root symbioses ⿞legumes(plant family)...plants w/ beneficial bacteria in nodules ‣ ex)peas,beans,clover,alfalfa,soybeans,peanuts ⿞rhizobium(n fixing bacteria) ⿞root nodules form that house bacteria (as a result of ) • bacteria enter thru root hairs...start beneficial "infection" • enter special vesicle in cortex cells...called bacterioids • ~develop living,non-photosynthetic root cells ‣ why are root nodules pink? • leghemoglobin(produced by plants)..complexes o2 and helps keep oxygen low around roots so nitrogenase can fx ‣ mutualistic symbioses • bacteria supply nh4+ to plant • plant supplies CHO to bacteria ⿞mycorrhizae- white hyphal masses ‣ fungus gets fixed C ‣ plant received increased SA for water absorption and enhanced mineral absorbtion ‣ endomycorrhizae (arbusular)...glomeromycetes...(85% of plants have endomycorrhizae) ‣ ectomycorrhizae • alternative plant nutrition: ⿞epiphytes...non harming ‣ plant growing on another plant to achieve hight to access sunlight • ex) staghorn fern,spanish "moss",vanilla orchid(climbs) ⿞parasitic...suck nutrition out of other plants ‣ ex) mistletoe,doffer,indian pipe Chapter 27 • Eukarya ⿞multicellular ⿞heterotrophic • unique to animals ⿞motile ⿞diploid ⿞gametic life cycle ‣ small motile sperm & large nonmobile egg ‣ asexual reproduction unusual ⿞no cell wall • in Unikonta group,Opisthokont • cholesterol...only in many steroid hormones • recall...choanoflagellates...unicellular group sister to all animals ⿞unicellular or live in colonies ⿞sponges...some called choanocytes...basal group of animals ⿞common ancestor:770 mya • Phylum Porifera...."pore bearer" ⿞divides by mitotic divisions to produce saclike stx w/ out defined germ layers,muscle,or bone ⿞sessile ⿞lack symmetry ⿞lack tissues ⿞filter feeders ⿞several cell types ‣ choanocytes- collar cells- imp for feeding & sexual reproduction ‣ ameobocytes- communicates w/choanocyte to get food particle... produces spicules that give the sponge more support ‣ pore cells- porocytes- allow flow of h20 thru body wall • Phylum Cnidaria ⿞named after special stinging cells in epidermis (cnidicites) ⿞ hunters ‣ tentacles w/ nematocytes ‣ gastrovascular cavity (one opening) that food is taken into • secretes enzymes that digest prey...unused pieces released out same opening ⿞forms: ‣ hydrozoans:(ex:hydra) sessile ‣ scyphozoans-jellies:~ planktonic form ‣ cubozoans-sea wasps ‣ anthozoan- sea anemone:flower anemones,corals...stay in one place ⿞motile & sessile forms ⿞radial symm ⿞two tissue layers: ‣ endoderm- layer facing rise to gastrovascular epithelium that secretes enzymes ‣ ectoderm- facing outside..tentacles...have primitive nerve net in their epidermis coupled w/ muscle cells (allows it to expand & contract) • cambrian explosion:535-525 mys (cambrian period:542-488 mya) ⿞precambrian forms:generally soft...ex:grazers,filter feeders,scavengers ⿞cambrian forms:large forms of other phyla evolved...hunters & the hunted ‣ bilateral symm (1st appears 670 mya) ‣ adaptations for capturing prey • ex) improved locomotion,grasping appendages ‣ defensive adaptations for avoidance • ex) mineralized skeletons,spines,shells ⿞hypoth for cambrian explosion ‣ predator-prey interactions ‣ atmospheric o2 • 3% --> 12% • supports higher metabolic rates ‣ Hox genes- genes regulating other genes • their products regulate other genes involved in patterns of development ⿞ex) how many segments,where legs & arms go • highly conserved among animals • animal body plans (~ helps classify animals) ⿞symmetry- ‣ radial(thru central axis) • oral(opening) & aboral sides (opp of opening) • sessile or planktonic(floats around) forms...environment meets organism same on all sides ‣ bilateral(down middle) • dorsal(back) & ventral (front) • right & left • anterior(top) & posterior(bottom) • cephalization- concentration of nerve/control cells (that recieve and process info from environment) at anterior end of organism • motile- move head first ‣ none(ex:sponges) ⿞tissues- form from germ layers ‣ diploblastic • ectoderm- gives rise to epidermis,nerve net,& muscle cells • endoderm- gives rise to gastrodermis (produces enzymes & nutrient absorbtion) ‣ triploblastic • ectoderm- outside tissues • endoderm- lining of gut & organs • mesoderm- gives rise to muscles & skeleton ⿞coelom- body cavity(pockets) lined w/mesoderm w/ organs inside ‣ allows organs to move around inside ‣ can be present/absent..not much phylogenetic use • none(sponges) • evolutionary relationships among animals ⿞36 phyla,most estbl'd by 500 mya ⿞all animals share a common ancestor ⿞sponges are basal animals ⿞eumetazoa is a clade of animals w/ true tissues (all animals except sponges...metazoa) ⿞most animal phyla belong to the clade Bilateria ⿞most animals are invertebrates (35 phyla) ⿞chordoata is the1 phylum that includes vertebrates • know figure 27.10...know current phylogeny ‣ imp:porifera,cnideria,chordata,anthropoda ‣ metazoa,eumetazoa,ctenophora,bilaterial,dueterostomia(includes chordates),lophotrochozoa,ecdysozoa • ecdysozoans- nemotodes & arthropods ⿞motling- shed exoskeletons through process called ecdysis • lophotrochozoans ⿞lophophore ‣ finger like feeding stx allowing organisms to filter feed • ex) ectoprocts & brachiopods ⿞trochophore ‣ distinctive trochophore larva stage • ex) annelids • ctenophora- absence of some stxs,but have genes for nerves ⿞look like jellyfish,but no stinging cells,have sticky projections to catch prey • notes on paper • arthropod evolution ⿞segment fusion ⿞[exoskeleton(pariphis)...movement,support,desiccation prevention] ⿞jointed paired appendages ⿞appendage modification/specialization ‣ walk,feed,swim,copulate • invasion of land by animals ⿞multiple events ⿞arthropods (450 mya) ‣ insects (410 mya) • wings- outgrowths of cuticle/exoskeleton • tracheae (gas exchange)- tube system leading to holes on outside of body wall...reach every cell in the body • coevolution w/plants ⿞vertebrates (365 mya) ‣ tetrapods ‣ ex) tiktaalik...has tetrapod & fish characteristics...transitional animal • neck,head,eyes close together,arms from shoulder,ribs,ability to life body off ground,ability to respire • tetrapod body plan evolution ‣ fins -->limbs • forelimb bones,wrist,digits • full rib cage ⿞lung support • neck & shoulders ⿞head movement • skull ⿞eye placement ⿞basal tetrapods ‣ amphibians • gave rise to salamanders,caecilians,& frogs & toads • can live away from h20,but need it for reproduction[external fert • have lungs,but most respiration takes place across skin ⿞amniotes ‣ amniotic egg- • allows reproduction to take place in shell(hard or leathery) w/out h20 • albumin- egg white...nutrition • air space • yolk- nutrients • chorion- membrane used in gas exchange • allantois- contains waste • amnion- membrane closest to embryo...contains fluid ⿞reptiles/some mammals ‣ internal fert & required stx ‣ derived characters of amniotes • impermeable skin ⿞keratin- protein in skin cells ⿞scales,hair,feathers • ribcage/ventilation- holds lungs • limbs to elevate body- enhances movement • amniotic egg ⿞extra-embryonic membranes ⿞w/ or without shell • crocodiles more closely related to birds than other reptiles • don't exactly know where turtles developed from..but closer to birds and crocodiles • tuataras- lizard like...sister to squamates • squamates- snakes & lizards • features of non-flying(non-avian) reptiles ⿞scaly skin ⿞lungs ⿞internal fert ⿞3 or 4 chambered heart- increases efficiency ⿞ectothermic- get body heat from environment • transitional form....bired/reptile...archaeopteryx...~150 mya • derived characters of birds(clade of reptiles) ⿞wings/feathers ⿞no urinary bladder(dont store waste) ⿞single ovary ⿞4 chambered heart ⿞endothermic- maintain constant body temp generated from high metabolic rate ⿞light skeleton ⿞no teeth • mammals..began evolving ~200 mya...1st true mammals ~150 mya ⿞only increased in size after dinosaur extinction ⿞body hair & mammary glands ⿞basal group:monotremes (ex:platypus)...lay eggs..milk comes out of skin ⿞marsupials (ex:kangaroo) ‣ early developmental birth ‣ embryo crawls up to pouch,attaches to nipple,then continues development while attached ⿞eutherians (ex:monkeys,apes,humans) ‣ longer gestational period ⿞derived mammal features ‣ mammary glands ‣ hair,dermal fat- barrier layer to retain heat,assists endothermy ‣ larger brain ‣ 4 chambered heart ‣ endothermic ‣ teeth adapted to diet ‣ remodeled jaw ⿞humans closest living relative is chimpanzee & bonobos Chapter 32 • 4 tissue types ⿞epithelial ‣ stratified squamous- layers of flat cells..line places that need constant replacement (mouth,skin,anus) ‣ pseudostratified columnar epithelium- surface has cilia,lines trachea & oviduct,looks like multiple layers bc nuclei are in diff places,but really only one layer • apical surface- lines interior of trachea...ciliated..move mucus ‣ simple squamous epithelium- single layer of epithelial cells close to capillaries ‣ simple columnar epithelium- absorption of nutrients...small intestine ‣ cuboidal epithelium- kidney,composes glands(produce hormones) ⿞connective- all...cells in extracellular matrix(can be solid,rubbery,or liquid) (can be very minimal) ‣ loose connective tissue- fibroblasts...produce fibers(collagen & elastic fibers) padding around joints & organs ‣ fibrous connective tissue- fibroblasts...parallely oriented fibers tendons(bone to bone)/ligaments(muscle to bone) ‣ bone- osteocytes...hard dense solid ecm...collagen & elastin(not brittle)..very well vascularized ‣ adipose tissue- adipocytes...not much ecm..fat tissue(triglyceride droplets...enlarge or shrink due to weight changes)...imp for energy storage,protective padding,padding for unprotected organs ‣ cartilage- chondrocytes...rubbery ecm..found in joints(pads bone ends)..not vascularized(takes awhile to be repaired) ‣ blood- rbc,wbc,plasma(ecm..water based w/ many things dissolved in it) ⿞muscle ‣ skeletal- parallel muscle fibers..can contract/relax...voluntary control ‣ smooth- in internal organs- same proteins as in skeletal muscle..contract & relax...spindle shaped(close together),each has single nucleus..under nervous & hormonal control ‣ cardiac- similar to skeletal due to parallel arrangment,but also branched & connected(physically & electrically...must contract & pump as a unit) • intercalated disk- individual cells closely attached (p&e) ⿞nervous ‣ neurons- transmission of signals • dendrites- receive signals then moves down axon to some other cell ‣ glia- interspersed among neurons...assist in architecture(brain & spinal chord) & getting nutrients ⿞each organ system usually includes all 4 types • how stability is maintained • conformers- temp does what outside temp does • regulators- regulate temp internally...dsnt change w/ environment • homeostasis- maintenance of internal balance ⿞set point ⿞negative feedback- detecting change in set point,then processes occur that cause a decrease in that stimulus that make it return to the set point ⿞regulates: ‣ cellular pH (specific) ‣ intracellular [calcium] ‣ plasma glucose levels ‣ osmotic balance ⿞homeostasis--> change in variable detected by sensor/receptor--> control center sends order to response/effector which restores homeostasis • thermoregulation ⿞ectothermy ‣ internal eat source ‣ regulated to set point ‣ metabolically expensive ‣ mammals & birds ⿞ectothermy ‣ external heat source and behavior ‣ body temp can be adjusted ‣ invertebrates,fish,amphibians,non-avion reptiles • radiation & conduction(direct contact) allows heat absorption • evaporation & convection(moving substance transfers heat (ex:wind,water)) allow heat release • counter-current exchange system- blood going one direction transfers heat to blood going the other direction • human thermostat(sensor/control center) in hypothalamus • homeostasis ⿞positive feedback ‣ uncommon ‣ stimulus amplification ‣ culminates(gets more intense as it progresses) in the end of a process • ex) birth,suckling • Signal Coordination ⿞only certain signals are picked up by certain receptors (specific) ‣ nerves detect specific things then integrate to the brain to form the correct response ⿞long distance pathway- ex)spinal chord to toe ⿞cell to cell pathway- ex) release chemicals(hormones) to neighboring cells ⿞major pathways: ‣ stimulus causing endocrine cell to release hormones • signal travels to about every cell in the body,but only the cells with the appropriate receptors receive the stimulus and respond • target tissue:receptor specific • timeframe adaptive for gradual changes ‣ signaling by neurons- nerve cell to specific location(where the dendrites terminate)..faster pathway • target tissues:neurons,muscle cells,endocrine cells,exocrine cells • timeframe is adaptive for immediate changes • protein hormones cant cross cell membrane...initiates signal transduction pathway when they touch the receptor outside the cell • non protein hormones diffuse across membrane to intracellular receptor • evolution of hormone function ⿞prolactin(from common ancestor) for phylogenic relationships ‣ mammals:mammary gland dev,milk synth ‣ birds:reproduction,fat metabolism ‣ amphibians:delay of metamorphosis ‣ fish(FW):salt & water balance • Osmoregulation & excretion ⿞osmoregulation- salt & water balance ⿞nitrogen excretion- protein & nucleic acid breakdown ‣ ammonia(nh3) • hypoosmotic- less solutes dissolved in it • hyperosmotic- more solutes dissolved in it • environments of animals ⿞FW aquatic ‣ hypoosmotic(to tissues of organism) ⿞marine aquatic ‣ isoosmotic(") ‣ hyperosmotic(") ⿞terrestrial ‣ desiccating(") • osmolarity ⿞expression of total solute concentration ⿞expressed as osmotic pressure:milliosmoles/L (mOsm/L) ⿞sum of concentrations of all dissolved subs ⿞pure water= 0 mOsm/L ⿞sea water= 1000 mOsm/L ⿞freshwater ~ 15 mOsm/L (very low) ⿞humans & other terrestrial vertebrates ‣ blood plasma ~ 300 mOsm/L • NA+ 145 mM • K+ 5 mM • Cl- 110 mM


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