Scientists classify organisms and assign each organism a universally accepted name
To organize similar organisms So all scientists are discussing the same organisms (species) Species population of organisms that share similar characteristics and can breed with one another and produce fertile offspring Identified 1.5 million species so far Estimate 2-100 million have yet to be discovered
What tools can we use to show similarities in organisms? Cladistic analysis identifies and considers only those characteristics of organisms that are evolutionary innovations – new characteristics that arise as lineages evolve over time Cladogram – diagram that shows evolutionary relationships among a group of organisms
Modern Evolutionary ClassificationDarwin’s ideas about descent gaverise to the study of phylogeny –evolutionary relationships amongorganismsEvolutionary Classification – Groupingof organisms based on evolutionaryhistory
Genes of many organisms show important similarities at a molecular level. Similarities in DNA can be used to help determine classification and evolutionary relationships
Swedish botanist that developed a two-word naming system called BINOMIAL NOMENCLATURE Gives the Genus and species name, written in italics or underlined Language is usually Latin Example: House cat – Felis domesticus Dog – Canis familaris Human – Homo sapien
Domain (most inclusive, less in common) Kingdom Phylum Class Order Family Genus Species (less inclusive, more in common) Each level is called a TAXON; taxa (plural)
Black bear Giant Abert CoralGrizzly bear Red fox panda squirrel snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos
Currently, all organisms are grouped into 1 of 3 domains which reflect evolutionary relationships 1) Bacteria 2) Archaea 3) Eukarya EUKARYA ARCHAEA Kingdoms BACTERIA Eubacteria Archaebacteria Protista Plantae Fungi AnimaliaLUCA – last universal common ancestor
Contains only one kingdom – EubacteriaCell type: ProkaryoteCell structures: Cells with peptidoglycan# of cells: UnicellularNutrition: Autotroph or heterotrophExamples: Streptococcus, Escherichia coliThese are your ORDINARY, every-day bacteria.
E. coli This bacterium (brown) is being attacked by dozens of bacteriophages (viruses that attack bacteria)
Contains only one kingdom – ArchaebacteriaCell type: ProkaryoteCell structure: Cell walls without peptidoglycan# of cells: UnicellularNutrition: Autotroph or heterotrophExamples: Methanogens, halophiles, thermophilesThese are your EXTREME ENVIRONMENT organisms. Although they are unicellular, they are probably more closely related to humans than they are to Eubacteria.
Cell type: Eukaryote Cell structures: Cell walls of cellulose in some (but not all), some have chloroplasts # of cells: Most unicellular; some colonial; some multicellular Nutrition: Autotroph or heterotroph Examples: Amoeba, Paramecium, slime molds, giant kelp, algae
Bundles of ciliaTwo protozoans… This one is about to be eaten!
Cell type: Eukaryote Cell structures: Cell walls of chitin # of cells: Most multicellular; some unicellular Nutrition: Heterotroph Examples: Mushrooms, yeast, mold
Extreme close-up of the underside of a mushroom, showing the reproductive spores (brown dots).
Cell type: Eukaryote Cell structures: No cell walls or chloroplasts # of cells: Multicellular Nutrition: Heterotroph Examples: Sponges, jellyfish, sea anemones, worms, insects, fishes, mammals, birds, reptiles, amphibians
Kingdom Animalia Phylum Chordate Class Mammal Order Primates Family Hominidae Genus Homo Species Sapiens
Kingdom Animalia Phylum Chordate Class Mammalia Order Carnivora Family Felidae Genus Felis Species Domestica
Living Things are characterized by Eukaryotic Prokaryotic cells cells Important and differing which place them in characteristics Cell wall Domain such as Eukarya structures which place them in which is subdivided into Kingdom Kingdom Domain Domain Plantae Protista Bacteria Archaeawhich coincides with which coincides with Kingdom Kingdom Fungi Animalia Kingdom Kingdom Eubacteria Archaebacteria
Unicellular prokaryotes (no nucleus) May be autotrophic or heterotrophic Equally small, and appear the same Lack membrane-bound organelles such as mitochondria, ER, Golgi, Lysosomes,etc. Have cell walls, cell membrane & ribosomes DNA is in the cytoplasm in a circular shape (called nucleoid)
EUBACTERIA ARCHAEBACTERIA More diverse Cell wall lacks Live almost everywhere peptidoglycan (other organisms, soil, Different membrane fresh & salt water) lipids DNA more similar to Cell wall contains the eukaryotes than to carbohydrate eubacteria, suggesting peptidoglycan eukaryotes descended from archaebacteria Live in harsh conditions
Ribosome Cell CellPeptidoglycan wall membrane Flagellum DNA Pili
Prokaryotes are identified based on: 1) Shape 2) Cell wall composition 3) Method of movement
GRAM-POSITIVE GRAM-NEGATIVE After “Gram staining” After “Gram staining” they appear purpleish they appear pinkish Has thick layer of Has thin layer of peptidoglycan peptidoglycan Eg) B. anthracis Eg) E. coli (Anthrax!) Less often pathogenic Usually associated with most pathogenic bacteria
Some don‟t move on their own Others move by: 1) flagella 2) lash, snake or spiral forward 3) glide slowly along a layer of slime-like material they secrete
Obligate aerobes – must have oxygen to survive (Obligate means that the organisms are obliged, or required, by their life processes to live only in that particular way) Eg) Mycobacterium tuberculosis which causes TB Obligate anaerobes – killed by oxygen Eg) Clostridium botulinum can grow in canned food that hasn‟t been sterilized properly Facultative anaerobes – survive with or without oxygen Metabolic pathways can alternate between using oxygen or not using it. Eg) E. coli is a facultative anaerobe that lives anaerobically in the large intestine and aerobically in sewage or contaminated water.
Asexual using binary fission DNA is replicated, cell splits in two. Similar to mitosis. Can happen as quickly as 20 minutes.
Mutations – mistakes during DNA replication Conjugation – the exchange of plasmid DNA between two bacteria Can form a pili (tube-like structure) that serves as a transfer tunnel for the plasmid Transformation - engulf “naked” DNA from the environment and incorporate it into their genome Scientists “transform” bacteria to produce insulin
Can form endospores A thick-walled internal structure that protects the DNA and some cytoplasm during periods of environmental stress (drought, temp, lack of nutrients) Lay “dormant” (inactive) as an endospore until environmental conditions improve
Antibiotics – chemicals used to treat bacterial infection (kill bacteria) Antibiotic resistance – when populations of bacteria are no longer killed by a particular antibiotic Results from OVERUSE of antibiotics Happens quickly because bacteria reproduce so quickly, and “resistant” strains develop rapidly This is evolution in action!
some species live in the roots of plants and help plants absorb nitrogen from the soil some decay organic material allowing it to be recycled Used in sewage treatment used to make cheeses, sauerkraut, pickles used in pharmaceutical industry to make drugs Some cause disease such as tuberculosis, syphilis, scarlet fever, food poisoning, Lyme disease
Multicellular except for yeast Eukaryotic heterotrophs Extracellular digestion - Fungi secrete enzymes into the environment, break down organic matter, then absorb the small nutrient particles Major decomposers Most are saprobes – digest nonliving organic matter Some are parasites, feeding off other living organisms
Body consists of cells joined to create filaments Each microscopic filament of a fungus is called a hypha Hyphae may form a huge tangled interwoven network called mycelium which can become visible bread mold Cell walls are made of a polysaccharide called chitin
NucleiCell wall Cytoplasm Cross wall Nuclei Cytoplasm Cell wall Hyphae With Cross Walls Hyphae Without Cross Walls
Most often is asexual Filaments break from the main mycelium and grow into new, identical individuals Fungus may produce spores Spores disperse, germinate, divide, and produce genetically identical fungi Spores can withstand extreme dryness and cold Sexual reproduction occurs No males or females, only (+) and (-) types Can happen when wandering hyphae meet
Lichens are associations between fungi and cyanobacteria or algae Cyanobacteria or algae are the photosynthetic elements Example of mutualism – a symbiotic relationship where both parties benefit The bacteria or algae provide nutrients for themselves and the fungus The fungus provides water and minerals for their metabolism Lichens exists in harsh habitats Can be found on mountaintops, rock faces in the desert, and tree bark Often first to enter barren environments, breaking down rocks – help in early stages of soil formation
General structure of lichensDensely packedhyphae Layer of algae/ cyanobacteriaLoosely packedhyphaeDensely packedhyphae
Heterotrophic Eukaryotes Mostly multicelluar Cell walls made of CHITIN Mostly DECOMPOSERS and SAPROBES Use EXTRACELLULAR DIGESTION Mold, mildew, yeast, mushroom, shelf fungi, ringworm
Includes everything except plants, animals, fungi & bacteria. In other words, they are the “everything else” kingdom. Very diverse group (over 200,000 species) All are eukaryotes (have a nucleus). Most unicellular, but some multicellular Believed to be the first eukaryotic organisms on Earth. “Protista” is Greek for “the very first” Biologists don‟t all agree on how to classify protists. Usually based on how they obtain nutrition – this is the system you will learn.
Commonly called protozoans All are heterotrophic Grouped into four major phyla Distinguished by their method of movement All are unicellular
Phylum: Zoomastigina Characteristics: Swim using 1, 2, or many flagella Absorb food through cell membrane Live in lakes, streams, and inside larger organisms Reproduction: usually asexual, but sometimes sexual Example: Trichomonas vaginalis – species that causes Trichomonias, an STD affecting ~180 million people worldwide each year. Trypanosoma – causes African sleeping sickness Giardia – one more reason you don‟t drink stream water w/out boil
Phylum: Sarcodina Characteristics: Move and feed with pseudopods (“false feet”) The cytoplasm of the cell streams into the pseudopod, and the rest of the cell follows. This is called amoeboid movement. Food is surrounded by a pseudopod and taken into the cell. Some form tough outer shells and extend their pseudopods through openings in the shell. Reproduction: asexual Example: Amoebas Entamoeba causes amebic dysentery. Pseudopods
Phylum: Ciliophora Characteristics: Use cilia for feeding and movement Found in fresh & salt water Complex internal structure Important feature: Contractile vacuole Specialized to collect excess water and pump it out – maintains stable internal environment (homeostasis) Reproduction: usually asexual Example: Parameciumb
Phylum: Sporozoa Characteristics: Do not move on their own Parasitic – affect worms, fish, birds & humans Reproduction: sexual and asexual Example: Plasmodium causes malaria. Plasmodium reproduces sexually inside the female Anopheles mosquito without harming the mosquito. Mosquito bites transfer sporozoites into human blood – sporozoites reproduce asexually inside humans and destroy liver and blood cells.
Play essential roles in the living world Recycle nutrients Many organisms depend on them for food Cause enormous amounts of disease Fun example: Termites Termites eat wood, but do not have the necessary enzymes to break down the cellulose in wood. The zooflagellate Trichonympha lives inside the termites gut and produces cellulase, an enzyme that breaks down the cellulose so termites can absorb the nutrients.
Commonly called Algae Grouped into four major phyla All unicellular Autotrophic Absorb light with pigments (chlorophyll mainly) Some have accessory pigments, which absorb wavelengths of light that chlorophyll cannot – increases efficiency.
Phlyum: Euglenophyta Characteristics: Two flagella, no cell wall, chloroplasts In low light, can become heterotrophic Very similar to zooflagellates Reproduction: asexual – binary fission Example: Euglena
Phylum: Chrysophyta Characteristics: Chloroplasts contain bright yellow pigments, making chloroplast appear golden. Store food as oil instead of starch Reproduction: asexual and sexual Examples: Yellow-green algae Golden-brown algae
Phylum: Bacillariophyta Characteristics: Produce thin, delicate cell walls rich in silicon – the main component of glass. Amazing array of shapes
Phlyum: Pyrrophyta Characteristics: Half are photosynthetic, half are heterotrophic Two flagella Thick, external plates made of cellulose for protection Many are luminescent (give off light) when agitated Pyrrophyta means “fire plants” Reproduction: asexual – binary fission Example: Gonyaulax – causes “red tides” (read on for more info)
Common in fresh & salt water Important part of aquatic ecosystems Produce about half of the oxygen in the atmosphere Can cause serious problems Algal “blooms” Rapid population growth caused by increase in available nutrients (sewage, fertilizer runoff from fields) Can have drastic effects on the fish and insects nearby Example – Dinoflagellates Gonyaulax and Karenia Blooms of these produce the “red tide” because they are red in color Also produce a potentially dangerous toxin – filter-feeding clams eat the dinoflagellates, and the toxins accumulate in the clam. Eating clams and other shellfish with these toxins can cause serious illness, paralysis, and even death in humans and fish.
Multicellular Very similar to plants Live in water Grouped into three major phyla Sorted by their photosynthetic pigments
Phylum: Rhodophyta Characteristics: Live almost entirely in salt-water Contain chlorophyll a and phycobilin (a red pigment) Can live at great depths Play role in formation of coral reefs
Phlyum: Phaeophyta Characteristics: Live almost entirely in salt water Contain chlorophyll a and c as well as fucoxanthin (a brown pigment) Examples: Giant Kelp Rockweed (Fucus) – found on rocky coast of eastern US
Phlyum: Chlorophyta Characteristics: Live in fresh water and salt water Unicellular or multicellular Food stored as starch Chlorophylls and accessory pigments similar to land plants Reproduction: Some sexual, some asexual Some have a diploid and haploid stage – called alternation of generations Examples: Ulva (sea lettuce) Volvox
Major food source for life in the oceans Major source of oxygen on Earth Algae offers many valuable chemicals Treat stomach ulcers, high blood pressure, arthritis; make plastics, waxes, transistors, deodorants, toothpaste, paint, lubricants, artificial wood Often eaten! Used in sushi, ice cream, salad dressing, pudding & candy bars Can cause economic & health problems Toxins produced by “Red Tide” dinoflagellates
Heterotrophic – absorb nutrients from dead or decaying organic matter Lack chitin in their cell walls (fungi has chitin) Live on land and water Complex life cycles
Phylum: Acrasiomycota & Myxomycota Characteristics: Spend most life as free-living cells similar to amoebas When food supply is limited, go through a complex reproduction process: 1) individuals send chemical signals that attract other cells of same species 2) Thousands of cells aggregate into a large slug-like colony that begins to function as a single organism 3) The colony migrates for several centimeters then stops to produce a fruiting body which produces spores 4) Spores are scattered and develop into the single amoeba- like cells we started with. 5) The cycle continues
Phylum: Oomycota Characteristics: Thrive on dead or decaying organic matter in water (and sometimes land) Not true fungi Often grows in a manner similar to fungus Reproduction: Complex lifecycle involving sexual and asexual reproduction
Important as recyclers of organic material Produce rich topsoil Cause plant diseases Mildew, blights of grapes and tomatoes Responsible for potato famine of 1846 in Ireland Destroyed potato crop – 1 million people died of starvation, and another 1 million or so emigrated to the US and other countries.
All plants share the common ancestor of green algae Plants have adapted to live on land Characteristics: The same photosynthetic pigments in similar chloroplasts Cell walls with cellulose Food stored as starch Multicellular eukaryotes
Four major groups based on differences in: Water-conducting tissues Seeds Flowers
Cladogram of the major plant types Flowering plants Cone-bearing plants Ferns and their relatives Flowers; Seeds Mosses and Enclosed in Fruit their relatives Seeds Water-Conducting (Vascular) TissueGreen algae ancestor(a protist)
Non-Vascular lack vascular tissue for long-distance transportation of water and solutes; lack true roots, leaves or stems Vascular Have tissue specialized for the long-distance transport of water and solutes through a plant; have true roots, leaves and stems Much like a circulatory system
Called Bryophytes Includes: Mosses & Liverworts Cannot retain water or deliver it to other parts of the plant body Water must be absorbed directly from the surrounding air or another nearby source Small, short, require water for sperm/egg union
90% of all modern plants have vascular tissue & have true roots, leaves, & stems Characterized by the presence of a vascular system composed of two types of specialized tissue Xylem – tissue that carries the water and dissolved minerals upward in a plant made of dead cells Phloem – tissue conducts sugars and some water upward and downward in a plant (sap) made of living cells Both xylem & phloem are distributed throughout the roots, leaves & stem
Roots Underground organs that absorb water and minerals; anchor plant Leaves Photosynthetic organs that contain one or more bundles of vascular tissue gathered into veins made of xylem and phloem; contain pores (stomata) for exchange of CO2 and O2 Stems Supporting structures that connect roots and leaves, carrying water and nutrients between them.
Seedless Seeded Ferns produce spores Plants produce male (not seeds) by meiosis and female gametes and store them in cases (pollen/egg) which join on the underside of the to form an embryo. A leaf (frond) protective seed coat surrounds the embryo Once spores are and provides released, they nourishment during germinate into small early stages of plants if they reach development. moist ground Other examples Club mosses & horsetails
Undersides of fern fronds, showingthe bundles (sori) that contain spores.Ferns do not produce flowers or seeds!
Life cycle of a fern MEIOSIS Sporangium (2N) Haploid gametophyte (N) Diploid sporophyte (2N) Frond Young gametophyte Spores (N) Mature (N) sporophyte (2N) Developing sporophyte Mature (2N) Antheridium gametophyte (N) SpermGametophyte(N) Egg Sporophyte embryo (2N) Archegonium FERTILIZATION
Gymnosperms vascular plants that Angiosperms produce seeds vascular plants that lacking a protective produce seeds fruit enclosed and gymnosperm means protected by a fruit “naked seed” Are flowering plants Eg) conifers – firs, Oak, tulip, spruce, pines, cedar grass, corn, tomatoes
Flowers– used in sexual reproduction of angiosperms Stamen Pistil Pistil (female part) Anther Stigma Style Ovary (produce eggs) Filament Ovary Style (stalk that holds stigma) Stigma (sticky pollen collector) Stamen (male part) Anther (produce pollen) Filament (stalk that holds anther) Petals – attract pollinators Sepals – protect young flower as it develops Petal Sepal
Cuticle – layer of waxes on outer surface that helps prevent loss of water Epidermis – one cell thick layer that secretes the cuticle Stomata – openings for diffusion Guard cells – two cells on either side of stomata that allow diffusion of CO2, oxygen and water vapor into and out of plant for photosynthesis
Relative numbers of plant species Cone-bearing plants 760 species (gymnosperms)Ferns and Floweringtheir relatives plants11,000 species 235,000 species(seedless (angiosperms)vascular) Mosses and their relatives 15,600 species (nonvascular)
Multicellular (more than 1 cell) Eukaryotic (cells have nucleus) Heterotrophic (can‟t make own food) No cell walls (only a membrane)
Most animals have tissues Tissue - Group of cells that perform a similar function Eg. muscular, connective, nervous All tissues arise from 3 embryonic (“primitive”) layers Ectoderm (outer layer) Mesoderm (middle layer) Endoderm (inner layer) More primitive layers = more specialization can occur during development
With the exception of sponges, every animal is symmetrical Two types of symmetry: Radial – any number of imaginary planes can be drawn through the center, each dividing the body into equal halves Eg) bike tire, cantaloupe, beach ball Bilateral – only a single imaginary plane can divide the body into two equal halves Have a left/right, usually have front/back and upper/lower
Bilateral SymmetryRadial Symmetry Posterior end Anterior end Plane of symmetry Planes of symmetry
Animals with bilateral symmetry usually show cephalization. Cephalization – the concentration of sense organs and nerve cells at the front end of the body Cephal- Latin for “head” Cephalization allows animals to respond to the environment more quickly and in more complex ways than simpler creatures
Invertebrates (95% of animal species) No backbone insects, sea stars, jellyfish, sponges, worms Vertebrates (5% of animal species) Have a backbone Fish, amphibians, reptiles, birds, mammals
Kingdom Phlyum Class Order Family Genus Species In order of simple complex
The most simple animals These are the sponges No tissues, organs, mouth or gut Have a few specialized cells Have thousands of pores all over body
Water flowCentral cavity Choanocyte Pores Spicule Pore cell Pore Epidermal cell Archaeocyte The movement of water through the sponge provides a simple mechanism for feeding, respiration, circulation, and excretion.
Radial symmetry Have stinging tentacles arranged in circles around mouth Specialized cells with barbs & poison Simplest animals with symmetry & specialized tissues Hydras, jellyfishes, sea anemones & corals
Epidermis Mesoglea Gastroderm Tentacles Mesoglea Gastrovascular cavity Mouth/anus Mouth/anusGastrovascular Tentacles cavity Medusa Polyp Life cycle of cnidarians includes the polyp and medusa form Polyp – mouth points upward, usually sessile (attached to bottom) Medusa – mobile, bell-shaped body with the mouth on bottom
Structure of nematocyst – “Stinging cell” – for which Cnidarians get their name.
Simple worms Includes: tapeworms and flukes Soft, worms with simple tissues and organ systems Cephalization & bilateral symmetry Some are free-living, some are parasites
Eyespot Ganglia Freshwater flatworms have simple ganglia and nerve cords Head Nerve that run the length of the body. Gastrovascular cords The excretory system consists cavity of a network of tubules connected to flame cells thatFlatworms use a pharynx to suck remove excess water and cellfood into the gastrovascular cavity. Excretory wastes.Digested food diffuses from the systemcavity into other cells of the body.Eyespots in some Ovaryspecies detect light. Testes Mouth Pharynx Most flatworms are hermaphrodites, having male reproductive organs (testes) and female reproductive organs (ovaries) in the same organism. Flame cell Excretory tubule
Earthworms, leeches & more Have segmented bodies Complex organ systems
Anus Setae Body segments Gizzard Crop Dorsal blood vessel Clitellum Mouth Brain GanglionCircular muscle Ventral blood vessel Longitudinal Nephridia Ganglia Ring Reproductive muscle vessels organs
Amphibians! (salamanders, frogs, toads) Water & Land life stages Breathes with lungs as adult A lungless frog has been found (April „08) Moist skin with mucous glands Lacks scales & claws