The Animal Kingdom

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Homepage

• Introduction
• Exercise 1 Graph That Diversity
• Exercise 2 Find that Animal
• Exercise 3 Phylogenetic Relationships
• Exercise 3a.
• Exercise 3b.

Suggested Reading Links
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Introduction

• There are so many different organisms on Earth
• To help deal with the great diversity of
  organisms, scientists have assigned them into
  general groups called Kingdoms.
• The members of each Kingdom share physical
  characteristics and similar feeding patterns.
• There are five Kingdoms in all.
• The Kingdom Monera
• Microscopic organisms (bacteria and blue-green
  algae) that have their genetic material (DNA)
  loose in a single cell.
• The cell thus has no compartments where specific
  cell functions would be carried out.
• The Kingdom Protista
• One-celled organisms with compartmentalized
  cells. The genetic material that passes on the
  traits of parents to their offspring is located
  in a compartment called the nucleus.

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• Like the Kingdom Protista, the following three
  Kingdoms have cells with compartmentalized
  function. Organisms belonging to these Kingdoms,
  however, are composed of many cells and are much
  larger and more complex than the protists.
• The Kingdom Fungi
• Organisms (e.g., mushrooms and molds) that feed
  on non-living organic matter (deceased organisms
  and fecal material ). into their simpler
  chemical compounds.
• In the process these organisms decompose or
  breakdown the organic material into simpler
  chemicals.
• The Kingdom Plantae
• Organisms (e.g., trees, ferns and mosses) that
  make their own food using the energy from
  sunlight.
• The Kingdom Animalia
• All of the multi-celled organisms (like insects,
  fish and mammals) that depend on other living
  organisms for food

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Unit 6 Materials List

• Spinner
• Magnifying glass
• Game poster for phylogenetic tree
• Mystery Animal
• Phylum Representatives
• Amphioxus 9A
• Bristle worm 6A
• Clam 5A
• Coral 2C
• Crustacean 7A
• Fish 9B
• Fluke 3B
• Hydra 2B

• Insect 7B
• Jellyfish 2A
• Leech 6B
• Octopus 5B
• Planaria3C
• Roundworm 4
• Sand dollar/starfish 8
• Snail 5C
• Sponge 1
• Spider 7C
• Tapeworm 3A
• Urchin 8B

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The student will

• Understand the level of diversity (richness of
  species) that exists in the different kingdoms
• Learn how scientists group organisms in the
  animal kingdom by common characteristics
• Learn that scientists have different views on how
  organisms should be grouped.

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Exercise1. Graph that Diversity

• The Kingdom Animalia has by far, the greatest
  diversity of named organisms (approximately
  1,000,000 kinds or species)
• Compared to
• The Plantae (300,000 species),
• The Fungi (70,000 species)
• The Protista (31,000 species)
• The Monera (10,000 species).

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Objective

• Exercise 1 You have already been provided the
  numbers of described species for each Kingdom.
  However it is often easier to compare numbers by
  looking at them visually (in a picture called a
  graph).
• In this exercise students will compare the
  diversity among the kingdoms graphically.

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Directions

• Divide the class into groups of three or four
  students
• Each group will use graph paper (template
  provided for zeroxing on next page) to visually
  compare the diversity of organisms among the
  different Kingdoms using the three forms of graph
  listed below
• Bar graph (vertical and horizontal)
• Pie Chart
• Line Graph
• Examine the examples of graphs to help guide you
  in making your graphs.

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• Each group should make a bar graph, line graph,
  and pie chart using the numbers of species
  described (named) for each Kingdom listed again
  below

Animalia 1,000,000 species Plantae
300,000 species Fungi 70,000
species Protista 31,000 species Monera
10,000 species
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Graph paper template
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Example of a bar graph that compares the number
of students in different grades at a school.

• Vertical or Y-axis
• Horizontal or X-axis

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• When you are done checking your bar graph, look
  at the other graph types shown below.
• Then construct your own pie and line graphs
  after those shown.

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Time to check your answers
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Graphs
A. Vertical Bar Graph
or
B. Horizontal Bar Graph
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C. Pie Graph/Chart
D. Line Graph
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Exercise 2. Find That Animal

• This box contains a sample of the huge diversity
  of creatures that can be found throughout the
  animal kingdom. Some of these sure do not look
  much like animals but they are.

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Objective

• Exercise 2 familiarizes students with the
  characteristics/traits that are used by
  scientists to pigeon-hole animals (place them
  into groups based on traits they share in common).

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Directions

• Divide the class into groups of three or four
  students
• The specimens should be placed at stations around
  the room by number along with the picture and
  fact sheet for each animal
• Each group should visit each station and
• 1) Read the fact sheet that explains the body
  plan and other characteristics of this particular
  animal group
• 2) Examine the specimen noting the
  characteristics you have read about and any clues
  that will help you in recognizing this animal
  type should you see it again

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Directions cont..

• After you are finished looking at the animals and
  their descriptions
• Your teacher will spin the pointer on the game
  board and read out the number that it lands on.
• Each group should write this clue number down on
  a sheet of paper.
• The teacher will look up the number on the clue
  sheet and read the characteristics of this
  mystery animal to the class.
• Each group needs to attempt to match the
  description with the appropriate animal from
  their notes and and commit this name to writing
  under the clue sheet number.

End exercise
Clue Sheet on next page
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Spin Clue Characteristics
CLUE SHEET
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• Once all groups have made their decision and
  recorded it, the teacher will record on the board
  all of the choices made and how many groups made
  each one.
• Now you can check the answer on the next page
  and you can discuss the characteristics of the
  animal that make it unique versus similar to
  other specimens

• Repeat these steps as many times as desired.
• In the end, the group with the most correct
  answers WINS!!!!

Pictures and Fact Sheets follow The answer sheet
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ANSWER SHEET
Spin Clue Characteristic
Answer ID, type, Phylum

Continued
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Answer Sheet continued
Spin Clue Characteristic
Answer ID, type, Phylum

Picture key and Fact Sheets follow
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1. Porifera -Sponges

• Filter feeders on dead organic matter that rains
  down on them.
• 1st animals to consist of many cells.
• Their cells, however, are not specialized into
  tissues but are of four types
• Boundary- provide structure and protection from
  the external environment.
• Pore- border canals that water flows through
• Collar- line the walls of the central chamber.
  Circulate water through sponge trap food
  particles
• Amoeboid- slithers around, collecting food from
  the collars, digesting it and distributing the
  nutrients throughout the sponge

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• May have silica (glass), calcium carbonate
  (limestone) or a protein that makes them
  inedible.
• Defenses are necessary because the sponge is a
  sessile organism that is permanently anchored
  onto some substrate.
• Sponges cant run away from predators, so they do
  not have a nervous system.
• The sponge is covered with canals that permit
  water to enter into a central circulating
  chamber.
• Central chamber collar cells each has a long hair
  called a flagellum that forces water through the
  sponge so that food particles will be left behind
  trapped in the picket fence-like collar.
• Sponges vary in size from just a few millimeters
  to over a meter in diameter.

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2. Cnidaria- Jellyfishes, hydra, corals etc

• The Cnidaria or Coelenterata are the first
  organisms to have tissues.
• From outside to inside, these tissues are
  ectoderm (outer), mesoderm (middle) and endoderm
  (inner).
• Phylum can be recognized by its stinging cells
  called
• nematocysts.
• These cells are ectodermal and are continuously
  produced as they are used.
• They kill prey and defend the animal.

2-basic forms
Floating medusa
Anchored hydra
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• Endoderm lines the digestive cavity.
• Mesoderm is only present as buds or globs
  (mesoglea) between the other two layers.
• Mesoglea gives the Cnidaria their body shape and
  also gives the jellyfishes buoyancy, allowing
  them to float in the ocean currents.
• The Cnidaria have many characteristics that
  reflect an inactive or sessile life style.
• Radially symmetrical or circular (shaped much
  like a pie). This allows the sessile animal to
  interact with its environment from all
  directions.
• Cannot move away from predators and thus have
  stinging cells for defense.
• Nervous system is undeveloped and present only as
  a nerve net that permits pulsing contractions but
  no directed movement.
• Reproduction is asexual or vegetative through
  budding.
• Use their tentacles to set up water currents,
  which carry potential food items to these
  stationary organisms.

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2A Jellyfish

• The jellyfish takes on the medusa body shape as
  an adult animal.
• It uses buds of mesoderm to float in the seas.
• The largest jellyfish has a body that is 3 meters
  in diameter with tentacles extending 80 meters
  below the rest of the body.
• Generally, jellyfish are marine/ live in salt
  water where there is greater support offered to
  this floating organism.
• The largest species are located in cold waters.

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2B Hydra

• Hydras are found in both marine and fresh water
  systems.
• They are an example of the sessile or anchored
  form of the phylum Cnidaria.
• They wave their tentacles to bring food to their
  mouths and may contract and shrink in size in
  response to encounter with an adverse stimulus.
• The hydra gets its name from the Greek Goddess
  Hydra who wore snakes in her hair. The waving
  tentacles around the mouth give the hydra this
  same appearance.

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2C Coral

• Corals are hydra, which live in colonies.
• The specimen in this box is the calcium carbonate
  skeleton the coral hydra secrete around
  themselves.
• Each hole in the stone-like cylinder would
  contain a living individual hydra.
• Thus hydra with the aid of algae (plant-like
  seaweeds) build their own houses.
• Each species of coral builds a unique skeletal
  shape. Hence the names, star coral, fire coral,
  staghorn coral and finger coral.

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Flatworms Platyhelminthes

• Flatworms, with their three clearly defined cell
  layers (ectoderm, endoderm, mesoderm) and
  bilateral symmetry, represent an important
  advance in early animal evolution.

• Flatworms lack a body cavity and are flat so
  that materials can be
• transported to all parts of the body through
  simple diffusion.

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• The flatworms are the first organisms to possess
  some form of organ. These organs are simple
  kidneys called nephridia and are mesodermal in
  tissue origin as all organs are.

• The flatworms are capable of directed movement
• and thus have nerves and the concentration of
  nervous tissue
• in the head region, which is called
  cephalization.

• They also exhibit bilateral body symmetry with
  distinct right and left sides. Cephalization and
  bilateral symmetry facilitate movement towards
  and away from stimuli.

• The size of an individual flatworm is limited by
  the fact that it has no respiratory or
  circulatory system and all exchange of gases
  occurs through the skin through the process of
  diffusion.
• The body is paper thin to bathe all of the cells
  in oxygen.
• Because of these limitations most flatworms have
  taken on a parasitic existence where they exist
  off the nutrients produced by other organisms.
• Two examples are provided here of parasitic
  forms along with one free-living form.

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3A Liver Fluke

• The flukes live as parasites on or in animals.
• Most flukes have large sucker-like mouthparts and
  many attack fish.
• The animal pictured here is a swordfish fluke.
• On your specimen, the white central area is full
  of reproductive organs as that is what parasites
  do reproduce thousands of offspring.

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3B Tapeworm

• The tapeworm above is about 90 cm long, much
  bigger than the dog tapeworm you have embedded in
  plastic.
• All tapeworms spend the adult phase of their
  lives as parasites in the guts of their primary
  host animals.
• Tapeworms also spend other parts of their life
  cycle in the tissues of one or more other animals
  (called intermediate hosts).

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• An adult tapeworm consists of
• a knoblike head, or scolex, equipped with hooks
  for attaching to the intestinal wall of the host
• A neck region
• A series of flat, rectangular body segments, or
  proglottids, generated by the neck
• The chain of proglottids may reach a length of 15
  or 20 ft and are the reproductive segments. Each
  can produce a new worm as its breaks off from the
  chain and is passed though the gut in feces.

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3C Planaria

• The planaria are free-living flatworms.
• They search for their own food and are not
  dependent on a host as parasitic flatworms are.
• Planaria, in fact are carnivores (meat eaters).
  They creep along the bottom of ponds or under
  rocks in streams seeking prey.
• They are also known for their great power of
  regeneration in which the two pieces of an
  individual each replaces its missing parts
  following the initial split.

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4 Pseudocoelomates

• The pseudoceolomate phyla
• are grouped together because
• they all have what is called a
• false body cavity, that is lined
• on the inside by endoderm and
• on the outside by mesoderm.

• This type of body cavity functions to give
• the body shape as it is filled with fluid.
• It is also important to movement which
• occurs through opposing muscle masses
• applying pressure on the fluid filled cavity.
• This deforms the flexible body wall. Needless
• to say movement is a non directed
• flip flopping in the pseudocoelomate worms.

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4 Roundworms/ Phylum Nematoda

• The roundworms are the most abundant animals in
  the World, with as many as 1.5 million
  individuals in a cubic foot of soil.
• Most are parasitic and perhaps the worm that is
  found encysted in pork is the best known as it
  causes trichinosis in humans.
• Many roundworms are important parasites and
  consumers of crop plants so they are of
  considerable economic importance.
• Roundworms are tapered at both ends and utilize a
  hydrostatic skeleton to move (opposing muscles
  acting on a fluid filled body). They merely flip
  flop.
• Since the roundworm has such an inefficient form
  of locomotion, parasitism is a good feeding mode
  for it.
• Your specimen is a dog roundworm. That is, it
  lives in the digestive tracts of dogs, stealing
  nutrients from their hosts.

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5 Molluscs/ Phylum Mollusca

• Mollusc (soft shell). All molluscs have a shell,
  but in the squids and octopi, it is greatly
  reduced and internal.
• Very successful group that was even more
  prominent in the seas before the introduction of
  the fishes.
• The archetype is a schematic of what is
  considered to be the generalized ancestor of
  modern groups.

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• Two features are present, a muscular head foot
  and a mantle cavity that serves in gas exchange
  and the ridding of wastes (excretion).
• Modern forms have either emphasized the head foot
  (the snails and chitons) or the mantle cavity
  (the clams and squids).
• There are about 75,000 species in marine,
  freshwater and even terrestrial systems (the land
  snails)

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5A Clams
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• Clams belong to the mollusc class, Bivalvia
  because they possess two shells housing greatly
  expanded gills
• In addition to providing for gas exchange, the
  the gills are used in filter feeding, trapping
  particles much as occurs in the sponge collar
  cell.
• In other molluscs, the gills are much smaller and
  are used only for gas exchange.
• Your specimen is only one shell of a clam.
• The two halves would have been attached at the
  narrow dorsal end of this shell.
• The mouth and gills would have extended ventrally
  towards the shell edge that opens exposing them
  when the animal is feeding.

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5B Octopus

• The octopus is an active predatory mollusc that
  is found worldwide in tropical and warm temperate
  marine waters.
• They range in size from less than an inch (2.54
  cm) to 15 feet (5 meters) in length.
• The octopus uses its mantle cavity as a jet
  propulsion mechanism for fast locomotion.
• Water is sucked into the chamber and forced out
  through the use of opposing muscle masses that
  surround the cavity.
• The octopus has a well-developed brain and keen
  eyesight for hunting at night.

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• The octopus seizes its prey with its eight long
  arms. These arms bear two rows of suckers each.
• The hundreds of suckers that line their arms help
  the octopus to hold on to their prey, mainly
  crustaceans (shrimp, crabs etc.).
• If an octopus loses one of its tentacles, it
  will soon grow another one in the same place.

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5C Snails

• Snails (Gastropods) have only one shell
  naturally.
• This shell opens at only one end and is twisted
  into a spiral coil with a gradually increasing
  diameter towards the opening.
• Most coils have a right-handed spiral. Looking
  from the opening up to the tip, what is the
  direction of the spiral on your specimen? Why
  does the snail have a spiral?
• The need to carry the shell to one side and its
  coiling is related to the fact that snails have a
  twisted gut that brings the mantle cavity and
  gills to the front of the body. This modification
  helped the larval snail to escape predation as it
  permitted it to pull its head into the shell
  first as opposed to the tail which is less vital
  to survival.

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6 Segmented Worms/Phylum Annelida

• The annelid worms have increased the efficiency
  of the hydrostatic skeleton that utilizes
  opposing muscles a fluid-filled body cavity and a
  flexible body wall.
• The body cavity has been divided into segments
  with individual muscles, nerves etc. This permits
  the more controlled movement required of a
  burrowing animal.
• In the ancestral segmented worms, there may have
  been as many as 200 segments.

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• There are three classes of segmented worms
• Primitive marine worms that swim with fleshy
  limbs called parapodia
• Terrestial burrowing earthworms
• The parasitic leeches which feed on the blood of
  vertebrates

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6A Bristle Worm

• A bristle worm is a member of the marine worm
  class Polychaeta.
• Each segment of the worm has a pair of fleshy
  limbs called parapodia or almost feet that are
  used in crawling on or burrowing in the seafloor.
  
• Most polychaetes are predators and can also swim
  in an undulating fashion.

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6B Leech

• Most leeches are parasites
• They have a sucker at the mouth and sometimes the
  tail that are used in attaching to the host
  during feeding.
• The leech used as bait by fisherman is a
  scavenger in streams and ponds, not a parasite.
• It has suckers at both ends for attachment to
  rocks.
• Leeches were used in the past to bleed humans
  when they were sick (ridding them of bad blood).
• Few species of leeches are parasitic on humans.

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7 Phylum Arthropoda

• The Arthropods are specialized, segmented
  animals.
• Movement has both increased in efficiency over
  the annelids and diversified through the
  reduction in the number of segments through
  fusion and specialization for a variety of
  functions.
• For instance, some of the segments are present
  as mouthparts and each pair of legs differs in
  shape and function.
• There has also been the development of a hard
  external skeleton for the legs to push against.
• This eliminated the functioning of a hydrostatic
  skeleton.

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• The arthropods use a lever system, hence the name
  joint-legged.
• The hard exoskeleton also does not permit gas
  exchange through the body surface. Thus
  respiratory tube systems have been developed,
  though gas exchange between the tubes and tissue
  is still passive through diffusion (no lungs).
• The arthropods are the most successful of all
  animals in terms of numbers of species.
• Of the three major classes, the crabs, spiders
  and their relatives, and insects, the insects are
  the most successful. The development of wings in
  insects is responsible for this success.

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7A Class Crustacea

• Members of the arthropod class Crustacea are
  primarily aquatic, though the amphipods (pill
  bugs) are a terrestrial example.
• Your specimen is a krill.
• The krill are small shrimp-like crustaceans,
  which are the most important zooplankton species
  associated with the sea ice and play a key role
  in the Antarctic food web.
• Krill occur in groups or large swarms and feed
  primarily on phytoplankton or sea ice algae.

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• The krill's feeding apparatus is built to filter
  phytoplankton out of the water column and to
  scrape algae from the ice.
• Krill are the main food source of small fish in
  the Antarctic seas.
• Note the jointed legs and claws and the hard
  exoskeleton that are characteristic arthropod
  features.

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7B Class Insecta

• Note the wings on the horse fly. These are an
  example of specialized segments characteristic of
  the arthropods.
• It is the wings that insects possess that have
  led to their tremendous success in terrestrial
  habitats. Winged insects can readily disperse
  from one habitat into another and move between
  feeding patches.
• There are more different insect species in the
  World than there are of any other organism.
• You can use the wing pictures above to help you
  identify the type of insect you have in your box.
  
• Insect legs and mouthparts are also used in their
  identification.

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7C Class Arachnida

• Spiders belong to the arthropod class Arachnida.
• The arachnids have
• four pairs of walking legs,
• an accessory pair of pincher-like appendages in
  the front that have fangs and are used in
  subduing prey,
• two main body segments.
• Spiders are all predators and are best known for
  their use of silk.
• About half of the 30,000 described species of
  spiders build web traps.

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• All spiders, including the ambush and wandering
  types use silk as a dragline to prevent injury
  from falls and to encase their eggs in a
  protective environment.
• Spiders have external digestion, taking only
  liquid meals.

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8 Echinoderms/Phylum Echinodermata

• The echinoderms have complex body plans but
  superficially look more like the sponges than the
  chordates, their closest relatives.
• The larval stage is bilaterally symmetrical like
  all of the advanced animal groups.
• The adults have a radial body symmetry reflecting
  the sedentary lifestyle they exhibit.

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• The primitive group, the crinoids were anchored
  like sponges, and the star fish, sea cucumbers
  and sea urchins all are slow moving with movement
  achieved through a hydrostatic skeleton
• Echinoderms are named because of the bony plates
  they possess in their exoskeletons.
• All members of this animal group are marine.

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8A Class Asteroidea Starfish

• True starfish are distinguished from the brittle
  stars in that they have no sharp demarcation
  between the arms and central body.
• In fact the sand dollars do not have distinct
  arms but only a central disk.
• Starfish move only through tube feet rather than
  by wiggling their arms.
• The starfish are the most speciose of the
  predatory echinoderm classes.

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• They use their tube feet shown above to pry open
  clams, which are preferred food items.
• Some starfish can extrude part of their stomachs
  out through the mouth, and thus digest food
  outside of the body.

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8B Class Echinoidea Sea Urchins

• Urchins are browsers The sea urchin uses a
  conveyor belt-like apparatus called a radula to
  scrape algae off rocks in shallow marine waters
  or on coral reefs.
• The specimen you have lacks the protective spines
  shown in this picture. This is because all that
  remains is the calcareous skeleton called a
  teste.
• The teste clearly shows the radial body symmetry
  of the echinoderm and in the living specimen, a
  spine would extend out of each pimple on the
  teste.

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9 Chordata

• The chordates all have a dorsal hollow nerve
  chord, a flexible skeletal rod called a notochord
  and gill slits at some stage in the life cycle.

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9A Cephalochordata

• While members of the subphylum Cephalochordata
  look like fish, they are advanced burrowing
  animals that have the notochord in the adult
  stage.
• The lancelet, Amphioxus is a filter-feeder that
  buries itself in the sea floor in shallow marine
  waters.
• It uses its notochord to aid in burrowing. The
  gills, which are used in breathing also collect
  small food particles floating by.

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9B Subphylum Vertebrata/ Bony Fish Class

• Fish are representative vertebrates, chordates
  that have the dorsal hollow nerve chord protected
  by ectodermal material.
• These bones take on the form of a segmented
  skeleton.
• In more advanced vertebrates a pelvic girdle is
  hung from the vertebral column to support the
  limbs
• In most vertebrates, the notochord is only
  present during embryonic development.

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• It is the protection of the nervous system and
  its greater development that has led to the
  tremendous success of this subphylum of
  chordates.
• Fish have two characteristics that have led to
  their great success.
• First, they have lateral (side) fins that allow
  for increased speed and turning compared to the
  early verterbrates and swimming, non-vertebrate
  chordates.
• Second, fish can breathe while stationary by
  muscular operation of a protective flap
  (operculum) over their gills. The moving
  operculum draws water through the mouth, over the
  gills and expells the oxygen depleted water back
  out.

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Exercise 3. Relatives of Relatives

• Figure 1a resembles a tree.
• It represents the phylogenetic tree for the major
  types of organisms in the Kingdom Animalia.
• A phylogenetic tree is used to show the historic
  relationships among a group of organisms.
• At the base of the trunk are organisms that
  appeared first in history
• They are the ancestors of other groups of
  organisms that branch off of the trunk as each
  gains new characteristics.

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Fig. 1a. Phylogenetic Tree for Major Phyla of
Animal Kingdom
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• Thus, this tree demonstrates the idea that new
  kinds of
• animals come into existence as modifications
  appear
• in existing animals. As a result, the Animal
  Kingdom
• today has 30 phyla, each with a distinctive body
  plan

The major changes in body plan that have occurred
over time have been added to the tree in Fig. 1b

• Examine Fig 1b, noting the different changes in
  body
• plan that have occurred with the appearance of
  new
• branches.

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Fig.1b. Changes in body plan added (-------)
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• For example, the sponges are the first branch of
  multicellular animals. Organisms below the
  sponges were single celled and not included in
  the Animal Kingdom. One-celled organisms are the
  acestors of animals that are all multicellular.
• And the jellyfish and corals branched off even
  higher than the sponges as the multiple cells
  they possess are specialized into tissues that
  perform different functions in the body Ectoderm,
  endoderm mesoderm.

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• Ectodermal tissue
• Forms the boundary layer between the contents of
  an animals body and the external environment.
• It also provides structural support in many
  animals
• Skin, hair, feathers, fur and bones are examples
  of ectodermal tissue.
• The stinging cells of jellyfish corals are also
  ectodermal.
• Endodermal tissue
• Is associated with the digestion of food
• The guts of all animals above the sponges on the
  tree are lined with endodermal tissue.
• Mesodermal tissue
• Muscles
• Organs such as the heart, lungs and kidneys

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• Once a new characteristic develops along the main
  trunk of the tree, all new branches that come off
  of the trunk have the new characteristic.
• Example Organs first appeared in the flatworms
  in the form of primitive kidneys that removed
  waste. The animal groups on all of the branches
  above the flatworms have some form of kidney.
• Other organs such as the heart, lungs and liver
  first appear in animal groups that are further up
  on the phylogenetic tree. These organs are
  developed into increasingly more complex
  structures in the higher branches.

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• Notice that the trunk of the tree splits into two
  smaller (secondary) trunks after the appearance
  of the clams and their relatives representing the
  molluscs.
• The animal groups formed after the split are
  related to members of the opposite branch only to
  the extent that their ancestors were organisms on
  the main trunk before the split occurred.
• Thus, the annelid worm group to which the
  earthworms belong is according to this historical
  tree the ancestor of the arthropods (insects,
  spiders, and crabs) but is not the ancestor of
  the vertebrates (fish, amphibia, reptiles, birds
  and mammals).
• Rather, the vertebrates are more closely related
  to the echinoderms (starfish, sea urchins and sea
  cucumbers).

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Objective

• Exercise 3 permits students to use their new
  knowledge about the organisms characteristics by
  asking them to construct a phylogenetic tree

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Exercise 3a. Understanding Historical
Relationships

• Now that you know how the phylogenetic tree
  works, see if you can determine where all of the
  animals in the trunk go on the tree.
• Study Fig. 1b noting the changes in body plan
  that are associated with each branch and the
  animal group that is associated with the new
  feature.
• Now find the poster with a similar tree to that
  shown in Fig. 1 in the box. This tree has
  branches without the animal groups shown on it.
• It is also displayed on
  the next slide
• Lay out the poster on a flat surface at the front
  desk
• As a class decide and place each specimen on the
  tree branch you think it belongs on without
  referring to Fig. 1.
• Note A key to the colors on the tree is
  available (Hand Out). Each color represents a few
  characteristics that the animal must possess in
  order to fit on that branch.
• Use this key to help you place the animals in the
  appropriate position on the tree poster.

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KEY (handout)
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Time to check your answers
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Exercise 3b. Comparing Trees

• Figure 2 demonstrates an important aspect of
  biology and science in general. There may well be
  different hypotheses as to how systems function
  and, in this case, how organisms are related to
  one another.
• Fig. 2. Comparison of two different proposed
  branching patterns for higher invertebrates

Based on one gene presence/absence of cuticle
skin covering
Based on pattern of development
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Directions

• Find examples of the animals that are represented
  in Fig. 2.
• Now compare the lineages shown in Fig. 2 to that
  you have been working with in Fig. 1.
• Note The lineage on the right side of the chart
  is the most widely accepted hypothesized tree.
• The tree on the left has been recently
  hypothesized to explain the molecular results of
  the analysis of one gene system.
• The animals possessing a skin covering called a
  cuticle that must be periodically shed during
  growth are more similar in their genetic make-up
  than the animals lacking this cuticle.

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• Question 1 Which animal groups are displaced in
  the tree depicted in Figure 2 from where they are
  located in the tree based on development?
• Stop!!! The answer is next!!
• The Arthropods including spiders, crabs and
  insects which have a true coelom or body cavity
  developed to house complex organ systems are
  taken out of the lineage containing other groups
  that have a true coelom (molluscks and segmented)
  worms) and moved into a lineage that includes
  organisms that have a false coelom or a body
  cavity designed mainly to provide shape in the
  absence of a skeleton.
• Question 2 How might the validity of the two
  alternative trees be tested?
• Stop!!! The answer is next!!
• One thing that can be done is to examine more
  genes to determine whether the relationships
  suggested with the sequencing of one gene are
  supported by other gene sequences.

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Suggested Reading

• The Beauty of the Beast Poems from the Animal
  KingdomJack Prelutsky, Meilo So (Illustrator),
  Meilo So (Illustrator)
• Sponges, Jellyfish and Other Simple Animals by
  Steve Parker, Daniel Gilpin, Steve Parker
  (Illustrator)
• Variation and Classification
• by Ann Fullick
• 4. Sponges, Jellyfish, and Other Simple Animals
  (Animal Kingdom Classification). Steve Parker.
• 5. Whats That Bug? Nan Froman. Illustrated by
  Julian Mulock.

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Links
Exercise 1 http//waynesword.palomar.edu/trfeb98.
htm Kingdoms http//www.worldagroforestrycentre.o
rg/sites/RSU/resources/biodiversity/analysistypes/
richness.asp Species Richness http//nces.ed.gov/
nceskids/graphing/creating graphs Exercise
2 http//waynesword.palomar.edu/trnov01.htm http
//cas.bellarmine.edu/tietjen/images/general_overv
iew_of_animal_phyla.htm http//ebiomedia.com/gall
/awob/index.html\
89
Exercise 3 http//aleph0.clarku.edu/djoyce/java/
Phyltree/cover.html constructing phylogenetic
trees http//www.tolweb.org/tree/ Tree of Life
Project