Entire classification pp

 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 Classification

Darwin’s ideas about descent gave
rise to the study of phylogeny –
evolutionary relationships among
organisms

Evolutionary Classification – Grouping
of organisms based on evolutionary
history

Appendages Conical Shells Crustaceans Gastropod

Crab Barnacle Limpet Crab Barnacle Limpet

Molted
exoskeleton

Segmentation

Tiny free-swimming larva
CLASSIFICATION
BASED ON VISIBLE CLADOGRAM
SIMILARITIES

 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 Coral
Grizzly 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
Animalia

LUCA – last universal common ancestor

 Contains only one kingdom – Eubacteria
Cell type: Prokaryote
Cell structures: Cells with peptidoglycan
# of cells: Unicellular
Nutrition: Autotroph or heterotroph
Examples: Streptococcus, Escherichia coli

These 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 – Archaebacteria
Cell type: Prokaryote
Cell structure: Cell walls without peptidoglycan
# of cells: Unicellular
Nutrition: Autotroph or heterotroph
Examples: Methanogens, halophiles, thermophiles

These are your EXTREME ENVIRONMENT
organisms. Although they are unicellular, they are
probably more closely related to humans than they
are to Eubacteria.

 Contains 4 kingdoms
 1) Protista
 2) Fungi
 3) Plantae
 4) Animalia

 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 cilia

Two 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).

ExtrEEEEEEEEme closeup of mushroom spores!

 Cell structures: Cell walls of cellulose; chloroplasts
 # of cells: Multicellular
 Nutrition: Autotroph
 Examples: Mosses, ferns, flowering plants

 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 Archaea

which 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 Cell
Peptidoglycan wall membrane

Flagellum DNA Pili

 Prokaryotes are identified based on:
 1) Shape
 2) Cell wall composition
 3) Method of movement

 Rod shaped (bacilli)
 Spherical (cocci)
 Spirilla (spiral & corkscrew-shaped)

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

Gram-positive cocci

Gram-negative bacillus

 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

Disease Pathogen Prevention
Tooth decay Streptococcus mutans Regular dental hygiene
Lyme disease Borrelia burgdorferi Protection from tick bites
Tetanus Clostridium tetani Current tetanus vaccination
Tuberculosis Mycobacterium tuberculosis Vaccination
Salmonella food poisoning Salmonella enteritidis Proper food-handling practices
Pneumonia Streptococcus pneumoniae Maintaining good health
Cholera Vibrio cholerae Clean water supplies

 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

The good…
…the bad…

…and the ugly.

 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

Nuclei

Cell wall
Cytoplasm

Cross wall
Nuclei

Cytoplasm Cell wall

Hyphae With Cross Walls Hyphae Without Cross Walls

Fruiting body

Hyphae

Mycelium

 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 lichens

Densely packed
hyphae

Layer of
algae/
cyanobacteria

Loosely packed
hyphae

Densely packed
hyphae

 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.

 Animal-like Protists – aka. “Protozoans”
 Zooflagellates, Sarcodines, Ciliates, Sporozoans
 Plant-like Protists – aka. “Algae”
 Unicellular Algae
 Euglenophytes, Chrysophytes, Diatoms, Dinoflagellates
 Multicellular Algae
 Red, Brown and Green Algae
 Fungus-like Protists
 Slime molds, water mold

 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
 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
 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
 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
 Two flagella, no cell wall, chloroplasts
 In low light, can become heterotrophic
 Very similar to zooflagellates
 Reproduction: asexual – binary fission
 Example:
 Euglena

 Phylum: Chrysophyta
 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
 Produce thin, delicate cell walls rich in silicon – the
main component of glass.
 Amazing array of shapes

 Phlyum: Pyrrophyta
 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.

Red Tide – La Jolla, California

 Multicellular
 Very similar to plants
 Live in water
 Grouped into three major phyla
 Sorted by their photosynthetic pigments

 Phylum: Rhodophyta
 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
 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
 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
 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
 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
 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) Tissue

Green 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

Life cycle of Mosses
Protonema
Haploid (N) (young gametophyte)
Diploid (2N) Spores (N)
MEIOSIS Male
(N)
gametophyte
Female
gametophyte
Mature
sporophyte
(2N)

Capsule
(sporangium) Antheridia

Sperm Archegonia
Gametophyte Young (N)
(N) sporophyte
(2N)

Zygote
(2N)
Sperm
Gametophyte (N)
(N)
Egg
(N)
FERTILIZATION

 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, showing
the 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)
Sperm

Gametophyte
(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

Guard cells Guard cells
Inner cell wall
Inner cell wall

Stoma

Stoma Open Stoma Closed

Cuticle
Veins
Epidermis

Xylem
Vein
Phloem

Epidermis

Stoma

Guard
cells

Relative numbers of plant species

Cone-bearing plants
760 species
(gymnosperms)

Ferns and Flowering
their relatives plants
11,000 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 Symmetry
Radial 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

Arthropod
Brain

Ganglia
Ganglia

Brain
Nerve
Cells

Flatworm
Cnidarian

Mollusk

 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 flow

Central 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/anus
Gastrovascular 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 that
Flatworms use a pharynx to suck remove excess water and cell
food into the gastrovascular cavity. Excretory wastes.
Digested food diffuses from the system
cavity into other cells of the body.
Eyespots in some Ovary
species 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
Ganglion
Circular muscle
Ventral
blood vessel
Longitudinal Nephridia Ganglia Ring Reproductive
muscle vessels organs

 Mollusks – snails, slugs, clams, squid, octopi
 Soft-bodied animals
 Usually have internal or external shell
 All have a body plan with 4 major parts:
 Foot, mantle, shell, internal organs

Squid

Snail
Shell

Mantle cavity

Foot

Clam Gills

Early Digestive tract
mollusk

Nudibranchs
-see latest issue of
National Geographic
for amazing pictures

 Insects, crustaceans, spiders, horseshoe crabs,
scorpions, lobsters
 Segmented body, tough exoskeleton, jointed
appendages (legs & antennae)
 Complex tissues & organ systems

Famous ancient sea-dwelling arthropod: Trilobites!

 Starfish, sea urchins, sea cucumbers, sea lilies,
sand dollars, brittle stars
 Spiny skin, internal skeleton, suction-cuplike
tube feet
 Usually 5-part radial symmetry

 Vertebrates (backbone)
 (exception: tunicates and lancelets)
 Backbone consisting of individual segments
called vertebrae
 We will look at the major classes

 Sharks, rays, skates
 Skeletons made of cartilage, not bone
 Teeth are made of bone!

 Bony fishes
 Skeletons made of bone

1) Agnatha
Jawless fish
Ex. Lamprey, hagfish

 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

 Snakes, turtles, lizards
 Dry, scaly skin
 Lungs
 Terrestrial (land) eggs
 Ecotherms

 Birds!
 Endotherms (regulate own body temp)
 Feathers
 2 legs covered with scales
 Front limbs modified into wings

 Mammals!
 HAIR
 MAMMARY GLANDS (produce milk)
 Breathe air

Chinese
Pangolin
Nine-Banded
Armadillo

Common
Echidna

Giant Anteater
Aardvark

Entire classification pp

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