Classification

The evolution of Complexity:

single cell prokaryote to multicellular eukaryotes

Aristotle to LinneausTaxonomy- classifying organisms, by placing

them into taxa

Binomial nomenclature is the system of assigning a scientific name to each species. Made up of genus and species.

Canis lupus, Turdis migratoris, Felis catus

Systematics- the study of biodiversity and its classification, create phylogenies

Phylogeny- an organism’s evolutionary history, a phylogenetic tree

Modern Classification System

• 3 Domains• 6 Kingdoms• Phylum • Class • Order• Family• Genus• Species

• 3 DomainArchea, Eubacteria, and Eukarya• 6 KingdomArcheabacteria, Eubacteria, Protista, Fungi, Plant, Animal• Genus First part of

Scientific name• Species Second part of

Scientific name

The Evolution of Complexity

• Earth is approximately 4.5 billion years old• 1st living things, prokaryotic bacteria cells

are found in the fossil record dating 3.5 billion years ago

• 1st eukaryotic cells appear in fossil record dating 2.1 billion years ago

• Between 635-530 million years ago the fossil record shows the diversity of algae and small animal like organisms

Origin of Life• Spontaneous Generation: life from non-life

was replaced with – Biogenesis• Oparin’s hypothesis of the origin of life

was tested by Miller and Urey, creating organic compounds like amino acids but not life

• Endosymbiosis- the hypothesis behind the evolution of eukaryotes from prokaryotes

• What is a Virus?- nonliving…

Composed of genetic material, RNA or DNA, and a protein coat

Genetic material surrounded by a protein coat, must have a host cell in order to reproduce

Life cycles: Lytic (kills host cell) or Lysogenic (incorporates DNA into host)

Human viral diseases

Virus- disease• Flavivirus- Yellow Fever• HIV- AIDS• Herpes virus 3- Chicken

pox• Filovirus- Ebola• Hepatitus B- Hepatitus• Influenza virus- Influenza

or pneumonia• Epstien- Barr virus- Mono

• Polio virus- Polio• Rhabdovirus- Rabies• Voriola virus- Smallpox• Paramyxovirus- Mumps

3 Domains

1. Archea2. Eubacteria3. Eukarya

Bacteria once belonged to the same Kingdom, Monera, but through Molecular Biology and the study of evolution, Biologist realized they had critical differences and should be placed into their own category so the “Domain” classification level was created.

6 Kingdoms

Archea and Eubacteria

• Archea KingdomAll prokaryotic single celled organisms. No Peptidoglycan in cell wall Most ancient and extremeThey live in the harshest environmentsMethanogens (anaerobic),

thermoacidophiles (hot) and halophiles (salty)

• Eubacteria KingdomTrue bacteria, all prokaryotic single celledHave Peptidoglycan in cell wallClassified by their shape and gram staining

Gram + have more peptidoglycan and stain purpleGram – have less peptidoglycan and stain pink

Shapes and Examples

• Sphere- Cocci, can occur in chains Streptococcus Pneumoniae which can cause strep throat or Scarlet fever, or grapelike clusters Staphylococcus aureus which can cause skin infections and Toxic Shock syndrome

• Rod- Bacillus ex Escherichia coli (E.coli), Lactobacilli which can cause tooth decay or one strain makes Sourdough bread, other bacilli can cause botulism, typhoid fever, and anthrax

• Spiral- Spirilla comes in 3 shapes 1. Vibro which is curved caused Cholera, 2. Spirillum (thick spiral), and 3. Spirochete (thin spiral) ex. Treponema pallidum causes Syphilis and another strain can cause Lyme disease

Images of bacteria

Strep- chainStaph - cluster

E. coli

Syphilis and Cholera

Essential Bacteria: ecosystems depend on these small organisms

• Cyanobacteria- photosynthetic/producers, building blocks of most aquatic food webs

• Nitrogen- Fixing Bacteria- symbiotic relationship with plants, they help them absorb nitrogen from the soil.

• Helpful: fermentation, digestion, biotechnology, nitrogen fixing, decomposers, oxygen producers

• Antibiotics kill bacteria by destroying the cell wall, gram negative have an extra lipid layer that prevents the antibiotics from entering the cell.

Reproduction• Bacteria reproduce asexually, binary fission• Each bacteria has a single chromosome but can

have additional DNA in the form of plasmids.• Plasmids increase Bacterial genetic variation

and contribute to Bacteria evolution• Plasmids can be exchanged between different

bacteria (even different species) by a process called conjugation.

• Plasmids can also be taken up by bacteria from their environment via transformation.

• Additional DNA recombination can be introduced via a bacteriophage, this is called transduction.

Review of Bacteria

All bacteria:• Reproduce asexually• Single celled• Have cell wall• Single strand of DNA

Some Bacteria:• Autotrophic • Heterotrophic• Some move by flagella, slime, spiral motion• Some produce endospores which allow them to go

dormant during hostile conditions• Some produce toxins

Kingdom Protista

• Kingdom of Mostly single celled organisms• Categorized by their likeness to 3 other

kingdoms• All Eukaryotic some Autotrophic and some

Heterotrophic

Algae- Plant like Protist

• Algae or Plant-like, Autotrophic, classified by pigment with no cell wall, come form elaborate colonies and multicellular structures (kelp and seaweed)

• Chrysophyta- Golden Algae ex diatoms• Pyrrophyta- bioluminescent/glow

ex. Dinoflagellates• Euglenaphyta- ex Euglena• Rhodophyta- red• Phaeophyta- brown, seaweed and kelp• Chlorophyta- green, ex Volvox, Spirogyra

Images of algae

• Volvox• Spirogyra• Red algae• Seaweed• Kelp• Diatoms

Protozoa or Animal like Protist

Protozoa or Animal-like, classified by mode of movement• Sarcodina ex. Amoeba- move by pseudopodia

“false foot”• Ciliophora ex Paramecium- move by cilia, tiny

hairs• Zoomastigina ex Trypanosoma (African Sleeping

Sickness) moves by flagella

• Sporozoa, are the parasitic animal like protista, include Plasmodium which causes Malaria

Images of Protozoa

• Amoeba• Paramecium• Trypanosoma

Fungus-like Protista• Fungus-like are all

Heterotrophic with no cell wall, absorbing nutrients directly through cell membrane

• Include Plasmodium or Slime Molds and Downy Mildews

Kingdom Fungi

• All Eukaryotic, multicellular, heterotrophs (saprotrophs or detrivores living off dead and decaying organisms or decomposers), cell wall made of chitin (type of protein), and classified by reproductive structures.

• Mycoses is the term for Fungal Infection, Fungus destroys the cells around the infection site, to fight fungal infection you have to destroy the cell wall

• Fungi are important part of an ecosystem because they recycle nutrients/ decomposers

Classifications of Fungi

• Club Fungi – Basidiomycota , Basidia, ex Mushrooms

• Sac Fungi- Ascomycota, Asci, ex. Truffles, Morels,Yeast, and Athletes Foot Fungus

• Zygote Fungi – Zygomycota, Sporangia, ex. Bread molds

• Imperfect- Deuteromycota, reproduce asexually, ex Penicillian

• Lichen- Mycophycophyta, symbiotic relationship between fungus and photosynthetic cells of cyanobacteria or algae.

Images of Fungi

Kingdom Plante

• Multicellular, Eukaryotic, Cell wall made of cellulose, Autotrophs, not capable of movement, reproduce sexually some produce spores and others seeds.

• Most have vascular tissues which include roots, stems, and leaves, and specialized tissues called xylem and phloem.

Plant evolution

• Evolved from green algae, 400-450 mya• Evidence: they both…

– Chlorophyll a, b, and carotenoids– Thylakoid membranes– Cell walls of cellulose– Stored carbohydrates as starch

**Primitive plants were aquatic, but adaptations have allowed them to be successful on land.

Plant evolution cont’d

• Adaptations to terrestrial life– Cuticle (leaf)- keep water in– Stoma (leaf)- control gas exchange– Development of specialized tissues

leaf, root, stem, root hairs, vascular tissue– Symbiosis with fungi and bacteria to increase

nutrient uptake– Secondary growth- lateral meristem to thicken

structures– Spores and seeds not dependent on water

Basic Plant Anatomy

• The leaf– Cuticle - Vascular bundles– Stoma - mesophyll

Figure 10.20 A review of photosynthesis

Guard cells Pore Stoma

18 µm

Leaf surfaces contain stomata

Photosynthesis relies on CO2 entering the leaf and O2 leaving the leaf

Leaf cross-section

CO2

Carbon dioxide diffuses into leaves through stomata

H2O

BUT: water also escapes through

the stomataThis is a

PROBLEM!

Spore Producing Divisions of Plant

9 Phyla of Plants: can be divided into spore or seed producers

Spore producers• Bryophyta only nonvascular plants, ex moss

and liverwort (gametophyte dominant stage of life cycle know as alternation of generations)

• Lycopodophyta ex. 1,000 species of Club and Spike moss

• Pterophytes 12,000 species of ferns, horsetails, and whisk ferns have compound leaves called fronds (dominant stage is the sporophyte)

Spore producing plant images

Seed producers

• Gymnosperms: reproductive structure is the cone , “naked seed”– Cycadophyta 130 species of these tropical

plants– Ginkgophyta 1 species remains the Gingko

tree– Coniferophyta 600 species of conifers, pine,

spruce, cypress, juniper, fir– Gnetophyta 75 species of these arid/semi-

desert dwelling plants

Seed producers

Angiosprems- reproductive structure is the flower, seeds are surrounded by fleshy or dry fruit that ripen to encourage animals to disperse the seeds.30,000 or more identified species

maple, hickory, oak, aloe, roses, tulips, dogwood, magnolia, corn, beans, tobacco, apple tree, pecan tree

2 classes:Monocots – with one seed leaf or cotyledon and

parallel veins on the leaf, orchids, lilies, grass, corn, grains

Dicots- with two seed leafs and branched veins on the leaf, roses, peas, beans, and oaks

Seed producers- gymnosperms

“Cone Bearers”

Seed plants- Angiosperm

Flowering Plant images

• Produce flowers and fruits (fleshy or dry)

Dry and Fleshy fruits

• Fruit is the mature ovary of the flower.

• It surrounds the seed and is often used to promote seed dispersal.

• Animals eat the fruit and seed and poop it somewhere else, this reduces competition with the parent plant.

Parts of a Flower• Pollination- fertilization of the female gamete

by the male gamete• Flowers are designed to attract a pollinator,

either by color, smell, or offer of food.• Birds, insects, and mammals act as pollinator

Other Plant Info.

Symbiotic relations ships: • Plants and Nitrogen fixing Bacteria• Flower patterns and scent attract

pollinators• Fruits promote seed dispersal by offering

a sweet reward to animals.

Plant Adaptations:

• Tropism- plant activities controled by hormones – phototropism (light), geotropism (gravity), and

thigmotropism (touch)

• specialized leaves (needles, spines, fuzzy, waxy) help reduce water loss in arid environments

Animalia

multicellular, eukaryotic, no cell wall, heterotrophs, capable of movement, reproduce sexually, body symmetry (radial or bilateral)

9 Phyla- 8 invertebrate and 1 vertebrate

Invertebrate- Porifera

• Porifera- two cell layers, collar cells w/flagella, filter feeders, ex. sponges

Invertebrate- Cnidarian

• Cnidarians- Stinging cells (nematocytes), radial symmetry, simple nervous system only stimulus and response, central cavity only one body opening, ex. jellyfish, coral, hydra, sea anemone

Invertebrate- worms

• Plathyhelmenthes: flat worms, only one body opening, three cell layers,ex. Tapeworm, Fluke, Planarian, Marine worms

• Nematode: round worms, first with two body openings, 3 cell layers, many parasitic, Heartworm, Roundworm, Vinegar Eel

• Annelid: segmented worms, two body openings, 3 cell layers, beginning of circulatory system, and digestive system (crop), ex. Earthworm and Leech

Worm images

• Plathyhelmenthes Nematode

• Annelid

Invertebrate Mollusk

• soft body, more complex body systems developing, eyes and nervous system, levels of communication beyond stimulus and response

3 classes • Gastropod (snails and slugs), • Cephalopod (squid octopus cuttlefish and

chambered nautilus), • Bivalve (oyster, clam, mussel, scallop)

Mollusk images

• Bivalves Gastropods Cephalopods

Invertebrate- Arthropod

• jointed legs, exoskeleton, body segments (head, thorax, and abdomen), metamorphosis (complete or incomplete)

4 classes:Insect -6 legs (ant, grasshopper, beetle, bee,

wasp)Arachnid -8 legs (spider, tick, horseshoe crab),Crustacean -10 legs (shrimp, lobster, barnacles,

crayfish)Myrapods -many legs, centipede and millipedes

Arthropod images

Invertebrate- Echinoderm

Characteristics: spiny skin, complex regeneration capacity, found only in marine environments, radial symmetry,

Examples: Sea urchin, Sand dollar, Starfish, Sea cucumber

Vertebrates- Chordata

Chordate notachord, complex body systems, sexual reproduction (internal or external fertilization) 5 classes:

Fish

Amphibians

Reptiles

Birds

Mammals

Fish

• Fish, moist skin covered in scales, gills to breathe, 2 chambered heart, cold blooded,

3 types:

1. bony ex Trout, Salmon, Bass, Catfish, Grouper, Tarpon.

2. jawless, ex. Lamprey and tunicates

3. cartilaginous ex. Sharks and Rays

Fish images

Amphibian

• Amphibian, cold blooded, 3 chambered heart, born in water, develop lungs, smooth moist skin, ex. salamander, newts, frogs, and toads (only dry skin)

Reptile

• Reptile, dry leathery skin with scales, cold blooded, most have a 3 chambered heart, amniote/terrestrial eggs, ex. Lizards, snakes, turtles, alligator, crocodile

Birds

• Bird, warm blooded, 4 chambered heart, hollow bones, body with feathers

Mammal• Mammal, warm blooded, 4 chambered heart,

milk producers, body with hair/fur• Placental (live birth), Marsupial (pouch) ex.

Kangaroo, and Monotremes (egg) ex Platypus

Animal Form

Body structure and development

Fig. 32-2-3

Zygote

Cleavage

Eight-cell stage

Cleavage Blastula

Cross sectionof blastula

Blastocoel

Gastrulation

BlastoporeGastrula

Archenteron

Ectoderm

Endoderm

Blastocoel

Remember this picture?Gastrulation of the blastospore

Fig. 32-3

OTHEREUKARYOTES

Choanoflagellates

Sponges

Other animals

An

imals

Individualchoanoflagellate

Collar cell(choanocyte)

True animals evolved from clusters of single cell flagellates (animal like Protista)

You can see how the sponge is really an asymmetrical cluster of nondifferentiated cells.

Fig. 32-7

(a) Radial symmetry

(b) Bilateral symmetry

Radial Symmetry aboveBilateral symmetry below

Animal Behaviors

Innate: 1. Instincts- complex pattern of innate behaviors,

reflexes, fight or flight, courtships, species recognition (language, song, flashes of pattern/light)

2. Territory- physical space needed for breeding, feeding, and shelter, organisms can expend a lot of energy defending territory some will fight to the death.

3. Migration- instinctive seasonal movement, response to a changing environment, includes hibernation (cold) and estivation (dry and hot)

Behaviors cont’d

Learned:• Habituation- animal repeats a successful

behavior, and does not repeat an unsuccessful behavior, birds learn which moths are poisonous by color and avoid eating them after becoming ill or getting a bad taste. Deer return to the same grazing field when successful.

• Imprinting – salmon and turtles return to same stream or beach to lay eggs in which they hatched, the environment left an imprint or memory

Adaptations for Defense:

• Mechanical- physical structures• Chemical- stinging sensations, poisons,

bad taste, paralysis• Camouflage- color or pattern that blend

into environment– Disruptive- ex zebra– Cryptic- ex chameleon and squid– Countershading- ex Fish have light belly and

dark back