Classification of Living Things

Tools Used to Classify Organisms

1. Comparative MorphologyCompares Physical Structures, Traits

2. Evolutionary RelationshipsRelated Organisms with common

ancestors, Derived Characters3. DNA/RNA comparison

Timeline of Classification1. 384 – 322 B.C. Aristotle

– 2 Kingdom Broad Classification2. 1735 - Carl Linnaeus

– 2 Kingdom Multi-divisional Classification– Kingdom, Phylum, Class, Order, Family

Genus, Species3. Evolutionary Classification – (After Darwin)

– Group By lines of Evolutionary Descent4. 5 Kingdom System – 1950s5. 6 Kingdom System – 1990s6. 3 Domain System – 1990s

Linnaeus Divisions Still Used in Modern Classification

1. Kingdom – largest group2. Phylum

3. Class4. Order

5. Family6. Genus 7. Species (Most Closely Related)

Mnemonic Device – To help remember categories and order

Kingdom - King

Phylum - Phillip

Class – Came

Order – Over

Family - For

Genus - Ginger

Species - Snaps

Taxons

Within each category, a particular group is called a Taxon

Many Taxons for each categoryEx: Mammalia is the Taxon for the Class

category in HumansEx: Homo is the Taxon for the Genus

category in HumansCarnivora is the Taxon for the Order

category in Lions

Linnaeus Introduced Scientific Naming• Binomial Nomenclature is the 2 word scientific

name of an organism– Uses Genus and Species

• Genus is capitalized, not species, all italicized• In writing the name, can’t italicize, so underline

– Homo sapien (Genus and species of Human)– Panthera leo (Genus and species of Lion)

Example Classification• Lion

• 1. Kingdom – Animalia (all Animals)

2. Phylum – Chordata (All vertebrate animals)

• 3. Class – Mammalia (All Mammals – mammary glands)

4. Order – Carnivora (Meat eaters)

5. Family – Felidae (includes all Cats)

6. Genus – Panthera (Includes all roaring Cats)

7. Species – leo (Lions)

From Kingdom to Species

6 Kingdom System

Animalia

Plantae

Fungi

Protista

Eubacteria

Archaeabacteria

Now, using the sheet like the chart below, fill in the pertinent data—as

described in the title—GET FROM ME!

3 Domains – write this in the domain name box.

• Eubacteria – Common Bacteria

• Archea Bacteria – ancient Bacteria

• Eukarya – Includes everything else, Protist, Fungi, Plants, and Animals

4. Three Domain System

1. Domain Bacteria – Corresponds to Eubacteria Kingdom (Characteristics)– Unicellular Prokaryotic Organisms

• No Nucleus • Ecologically Diverse – live everywhere!• Metabolically Diverse

– Cell Walls contain substance called Peptidoglycan – special protein and sugar

• Target of many Antibiotics

Three Domain System

• 2. Domain Archaea – “Ancient Bacteria”– Corresponds to Kingdom

Archaeabacteria– Unicellular, Prokaryotes

• Metabolically Diverse• No nucleus• Live in Extreme environments like

those of early Earth• Cell walls without Peptidoglycan

– A trait used to distinguish between Archaea and Bacteria Domains

Three Domain System

3. EukaryaContains Kingdoms:

Protista, Fungi, Plantae, AnimaliaEukaryotic, single or multi-cellular

OrganismsNucleusMost visible lifeHumans are in Domain Eukarya

BEFORE BEGINNING THIS SECTION, YOU’LL NEED ANOTHER SHEET FROM ME!

Invertebrate Overview:Kingdom Animalia

Phylum Porifera -spongesPhylum Cnidaria -jellyfish, sea anemonesPhylum Platyhelminthes -tapeworms, flukesPhylum Nematoda -pinworms, AscarisPhylum Mollusca -clams, squid, octopiPhylum Annelida -earthworms, leechesPhylum Arthropoda -insects, crayfishPhylum Echinodermata -starfish, sand dollars

Phylum Porifera

• Ex. Sponges• Multicellular WITHOUT TISSUES• Heterotrophic filter feeders• Asymmetrical• No cephalization present• No coelom• Basic body parts: ostia, spongocoel, osculum,

choanocytes with flagella

Figure 33.2 Sponges

Figure 33.3 Anatomy of a sponge

Porifera

Sponges are aquatic animals that represent a transition from unicellular to multicellular life. Of the 10,000 species of sponges, only about 150 species live in fresh water. Adult sponges are sessile, meaning that they attach themselves to a surface and do not move. Because they are sessile, sponges are filter feeders, screening food out of the water that flows through their body.

Porifera / Sponges

Phylum Cnidaria• Ex. Jellyfish• Two germ layers: ectoderm and endoderm• No cephalization• No coelom• Soft, sac-like body plan, two way digestion (with one

opening – mouth)• Two body forms: sessile polyp and free-swimming

medusa • Basic body parts: bell, cnidocytes with nematocysts,

tentacles, gastrovascular cavity, gonads

Figure 33.4bx Jelly medusa

Table 33.1 Classes of Phylum Cnidaria

Figure 33.4 Polyp and medusa forms of cnidarians

Figure 33.5 A cnidocyte of a hydra

CnidariaFreshwater hydra, jellyfish, and corals go through a transition in body forms. The medusa stage (bell-shaped) is specialized for swimming and the polyp stage (vase-shaped) is specialized for a sessile life. All members of the phylum have these two stages at one time in their life, even though the medusa stage may be found only as an embryo. All cnidarians have tentacles containing cnidocysts and nematocysts, specialized stinging cells for defense and capturing food.

Cnidaria / Hydra

Cnidaria / Coral

Cnidaria / Jellyfish

Phylum Platyhelminthes• Ex: tapeworms• Three germ layers: ectoderm, mesoderm, endoderm• Bilateral symmetry• Cephalization is present• No coelom – acoelomates!!!!• Use diffusion to transport materials through body• Mouth forms first – protostomes• Basic body parts: mouth, pharynx, intestine,

ganglia, flame cells

Figure 33.9x A flatworm

Figure 33.10 Anatomy of a planarian

Figure 33.12 Anatomy of a tapeworm

Phylum Nematoda

• Ex. Pinworms• Three germ layers present – ectoderm, mesoderm,

endoderm• unsegmented• Bilateral symmetry• Cephalization present• Pseudocoelom present • Mouth forms first – protostome• Basic body parts: mouth, anus, intestines

Figure 33.25a Free-living nematode

Figure 33.25ax Nematode, C. elegans

Nematoda

Roundworms have a long, slender body that tapers at both ends. They range in length from 1 millimeter to 4 feet in length. This phylum is the first to have a digestive tract with two openings, which is a major advancement over the phyla up to this point. The vast majority of these animals are free-living, but there are about 150 species that are plant and animal parasites.

Nematoda

Nematoda / Roundworms

Phylum Mollusca

• Ex. Clam, squid• Three germ layers present: ectoderm, mesoderm,

endoderm• Have an external or internal shell for support• Bilateral symmetry• Cephalization present• Has a TRUE COELOM• Mouth develops first – protostome• Basic body parts: gills, specialized “foot”

Table 33.3 Major Classes of Phylum Mollusca

Figure 33.18x Garden snail

Figure 33.20 A bivalve: Scallop

Figure 33.22 Cephalopods: Squid (top left and bottom left), nautilus (top right), octopus (bottom right)

Mollusca

Gastropoda: most members of this class have a one-piece, external shell. Gastropods include snails and slugs. Bivalvia: members have an external shell divided into two halves that are connected by a hinge. Bivalves include clams, oysters, and scallops. Cephalopoda:these marine mollusks are the most advanced group in the phylum. Their nervous and circulatory systems are highly advanced and they have an internal shell supporting the body. Octopus and squids are cephalopods, including the giant squid - the world's largest known invertebrate.  

Mollusca - Snails, Clams, Squid and Octopus are the first animals with a true coelom, a hollow, fluid-filled cavity completely surrounded by the mesoderm. The phylum is divided into three classes.

Mollusca / Octopus

Mollusca / Squid

Mollusca / Clams

Mollusca / Snails

Phylum Mollusca

Body Plan• Different shapes of Mollusks (clam, octopi)

are evolution of Basic Body Plan• Basic Plan: 4 Specific Mollusk Parts

– Foot – many shapes, parts; movement– Mantle – tissue that covers body– Shell – made by glands in mantle, covers body– Visceral Mass – contains internal organs

Shell

Mantle cavity

Foot

Gills

Digestive tract

Earlymollusk

Clam

Squid

Figure 27–21 The Mollusk Body Plan

Snail

FOOTMANTLE

SHELL

VISCERAL MASS

Feeding• All types of diets• Radula: Flexible, tongue like part with

hundreds of teeth attached– Scrape algae, soft tissues of plants or drill through

shells, tear soft tissue

• Sharp Jaws used by Octopi,Sea,Slugs– Can also contain poison

• Clams, Oysters, Scallops filter feed through Siphon– Food trapped on sticky Gills

Respiration and Circulation• Aquatic: Gills inside Mantle Cavity O2 Blood

Vessels• Land: Mantle Cavity O2 Blood Vessels

– Require moist lining• Open Circulatory System – carries O2, nutrients

– Heart pumps Blood to vessels– Vessels to Sinuses – Sinuses to Gills O2 picked up, CO2 released– Blood Back to Heart

Excretion• Cells Release Nitrogen Waste Blood• Nephridia Remove Nitrogen Waste Out of Body

Nephridium

Response• Complexity of Nervous System Varies• 2 Shelled Mollusks – Ganglia, Nerve Cords,

Simple Sense Organs– Clams

• Octopi – Brains; Memory!• Chromatophores – Skin Cell ability to change

skin color and texture to match surroundings– Most Intelligent Invert Animal– Can be trained to perform tasks

Movement

• Many Different Ways• Snails – S L O W….

– Secrete Mucus on Foot; Ripple Foot• Octopi – FAST

– Draws Water into Mantle, Forces out through Siphon

Reproduction• Snails and 2 Shelled – Sexually, External

– Release high # of Eggs and Sperm in water– Develop into free swimming larvae – Larvae called Trochophore

• Some Hermaphroditic• Tentacled Mollusks – Internal Fertilization

Class Gastropoda“Stomach Footed”

• Nudibranchs, Slugs, Snails• Ventral Muscular Foot to Move• 1 or no Shell• Can secrete toxins, ink• Ex: Nudibranchs can eat Cnidarians; Hijack

Nematocysts for Protection

Snail External Anatomy

Nudibranch with spiny tentacles

Class Bivalvia2 Shelled Mollusks

• Oysters, Clams, Mussels, Scallops• 2 Shells Held By 1 or 2 Muscles• Flap Shells, Burrow to Move• Filter Feed – Cilia on Gills Current• Can use Muscles near Mouth to get Food

Section 27-4

Mouth

Shell

Stomach CoelomHeart

Nephridium

Adductor muscle

Anus

Excurrentsiphon

Incurrentsiphon

Gills

Mantle cavity

Foot

Intestine

Mantle cavity

Adductormuscle

Anatomy of a Clam

Class Cephalopoda“Intelligent” Mollusks

•Octopi, Squid, Cuttlefish, Nautiluses•Head attached to Foot

•Complex Eyes•Foot -- Divided into Tentacles

•8+ with Suckers•Small Internal Shell – adapted or lost•Only Nautiluses have External Shell

Cephalopod Examples

Phylum Annelida

• Ex: earthworm• Three germ layers present• Bilateral symmetry present• Cephalization present• True coelom present• Mouth develops first – protostome• Basic body parts: mouth, anus, specialized

intestine, segments

Figure 33.23x External anatomy of an earthworm

AnneildaSegmented worms are more advanced than roundworms and have several visible characteristics that distinguish them. They are named for the many body segments that make an annelid look like it is composed of a series of "rings". Unlike roundworms, the segmented worms have an obvious head and tail. All segmented worms have one of two types of structures extending from their bodies that are used for locomotion. Most annelids have hair-like bristles known as setae

Segmented Worms

Figure 33.23 Anatomy of an earthworm

Phylum Arthropoda• Ex. Insects, spiders, crayfish, millipedes, centipedes• Three germ layers present• Exoskeleton present that requires molting (shedding)• Jointed appendages• Bilateral symmetry• Cephalization present• True coelom present• Mouth forms first• Basic body parts: head, thorax, abdomen, (or cephalothorax

and abdomen), spiracles and tracheae, open circulatory system

Table 33.5 Some Major Arthropod Classes

Figure 33.26 External anatomy of an arthropod

Figure 33.30b Spider anatomy

Figure 33.33 Anatomy of a grasshopper, an insect

Phylum Arthropoda

“Jointed Foot”Largest Animal Phylum

feedon

respireusing

reproduceusing

Section 28-1

havewell-developed

Concept MapAnthropods

Internalfertilization

All typesof foods

Externalfertilization

Heart Brain Muscles

Trachealtubes Book lungs Book gills

Phylum Overview• Most ‘successful’ Phylum of All Time• 750,000 species identified• Ex: Shrimp, Butterflies, Crabs, Spiders• Covered in hard Exoskeleton made of Chitin

– Gives Support– Adapted to environment – water

loss/protect• Jointed Appendages

– Legs, Antennae – Increased Muscle Need for Joint Movement

Evolution of Arthropods• 600 MYA – Appeared in Sea• Moved into all Environments

– Air, Water, Land• Body plan modified from many segment

origin• Trilobite Fossil 500MYA• Modern Arthropods – fewer segments,

more specialized appendages– Cephalothorax, Thorax, Abdomen, Head

The Exoskeleton

• Provides Protection, Support• Adapted to Environment, Lifestyle

– Fruit flies versus Lobsters

• Exoskeleton – environment specific– Specific to Oxygen requirements

– O2 level has changed, insect size has changed– Molting – shedding of exoskeleton to

accommodate for growth

Figure 33.27 A trilobite fossil

Appendages

• Jointed and attached to body segments• Evolved over time

– Wings, Legs, Antennae, Claws, Mouthparts, Tails, Flippers

• Adaptive Radiation – new characteristics can introduce arthropods to new habitats– Ex: Wing Evolution New Habitat (Sky)

Feeding

• All Types of Diet• Evolution – Mouthpart Adaptation and

Diversity–Extreme range of mouthparts –

biting, sucking, piercing, etc–Mandible – chewing jaw ‘joint’

Excretion

• Malpighian Tubules – Sac like organs– Extract wastes from Blood, add to feces

• Aquatic – Tubules excrete directly into water

• Compromise between exoskeleton protection with exchange of materials and gases

Respiration and Circulation

• 1. Terrestrial Insects Breath through Tracheal Tubes

• 2. Spiders – “Book Lungs”–Stacked Layers of Respiratory Tissue

• 3. Aquatic Arthropods – Feather-like Gills

• Open Circulatory System

Class Insecta• 3 Body Segments: Head, Thorax,

Abdomen • One/Two Pairs of Wings attached to

Thorax• 3 Pairs of Legs• Antennae Present• Metamorphosis – 2 Types

Figure 33.33 Anatomy of a grasshopper, an insect

Metamorphosis – Development Stages

• Incomplete – Immature Stage looks like smaller Adult Stage – Nymph Adult - Grasshopper

• Complete – Larval Stage specialized for growing– Look Different – Caterpillar/Butterfly

Section 28-3

IncompleteMetamorphosis

CompleteMetamorphosis

Eggs

Larva

Pupa

Adult

Nymph

Nymph

Nymph

AdultEggs

Larva

Adult

Adult

Immature

Metamorphosis

Figure 33.34 Metamorphosis of a butterfly

Class Crustacea• Lobsters, Shrimp, Crabs • 2 Body Segments – Abdomen Cephalothorax• Swimmerets –for swimming• 4 pairs of Walking Legs• Chelipeds - Pinchers• Gills• Mandible • Antennae

Figure 33.26 External anatomy of an arthropod

Class Arachnida • One/Two Main Body Parts – Cephalothorax,

Abdomen• 6 Pairs of Appendages – 2 Feeding, 4 walking• Fangs

– Secrete digestive juices and poisons• Book Lungs• No Antennae• Web-making –predation and mating behaviors

Figure 33.30b Spider anatomy

Figure 33.30x Lycosid spider: female with offspring

Ecology of Arthropods

• Compete with Humans for food• Pollinators • Provide food for Humans, food chain• Pesticide Pollution to Combat

Arthropods• Carry Disease

–Malaria

ArthropodaThree-fourths of all animal species, including spiders, crayfish, and insects, are arthropods. This phylum is composed of a very diverse group of animals that are bilaterally symmetrical. The following characteristics have allowed arthropods to adapt to almost every environment on Earth:

•Jointed appendages: the phylum name means "jointed foot". All the appendages (body extensions) of arthropods are jointed, giving them a wide range of controlled motions. •Exoskeleton: the exoskeleton provides support and protection. It is composed of three layers that are secreted by the epidermis.

Segmented body: the segments in the arthropod body make movement possible, even with the hard exoskeleton.

Arthropod / Spiders

Arthropod / Crayfish

Phylum Echinodermata

• Ex: starfish• 3 germ layers present• Biradial symmetry in adults• No cephalization in adults• True coelom present• Anus forms first – deuterostome!!!• Basic body parts: spiny skin, endoskeleton, water

vascular system, tube feet

Figure 33.37 Echinoderms: Sea star (top left), brittle star (top right), sea urchin (bottom left), sea lily (bottom right),

Figure 33.38 Anatomy of a sea star

EchinodermataStarfish, sand dollars, and sea urchins are found in marine environments ranging in depth from shallow tide pools to 10,000 meters. Most of the 7,000 species of echinoderms have a type of radial symmetry called pentaradial symmerty, in which the body parts extend from the center along five spokes.

•They have a water-vascular system - a network of water-filled canals inside their body.

They have many small, movable extensions of the water-vascular system called tube feet, which aid in movement, feeding, respiration, and excretion

Echinodermata / Starfish

Echinoderms / Sand dollars and Sea Urchins

Phylum Echinodermata

Spiny SkinStarfish, Sea Cucumbers, Sea Urchins,

Sand Dollars

Figure 33.37 Echinoderms: Sea star (top left), brittle star (top right), sea urchin (bottom left), sea lily (bottom right),

Phylum Overview

• Sessile/Slow Moving Animals• 5 Spines typical• Radial Symmetry• Thin ENDOSKELETON • Water Vascular System• Tube Feet • External Sexual Reproduction

Closest Relation to Chordates

• Develop from Bilateral Larvae• Deuterostomes – Developmental Pattern• Radial Cleavage • Mouth End Forms opposite of Anus End

Functions

• Water Vascular System -- Network of Hydraulic Canals– Radiate from center Tube Feet– Tube Feet – locomotion – Gas Exchange - Gills

• Feeding – Mouth on Bottom Short Digestive Tract Anus on Dorsal Side

Figure 33.38 Anatomy of a sea star