Download Classifying animals

Classifying Animals
The Invertebrates
Objectives:
1. Describe the characteristics used to classify
animals into different groups
2. Discuss the characteristics of animals in different
phyla
3. Explain how each successful phyla have become
more complex and able to occupy more diverse
habitats
Thinker…
• Why is it thought that prokaryotic cells
are more primitive than eukaryotic
cells?
Eubacteria
What Kingdom
do I belong to?
• I am Prokaryotic.
• I can live almost
anywhere.
• I reproduce asexually.
• I usually have a cell
wall.
• I am heterotrophic
(eat food) or
autotrophic (make my
own food.)
Plantae
• I am multicellular
• I have a cell wall
• I make my own food
(autotroph)
Protista
• I might be prokaryotic
or eukaryotic
• I live in moist habitats
• I can make my own
food but some of my
friends have to
consume their food
• I can be plant-like or
animal-like
• I can make you sick
Fungi
• I am a heterotroph
• I am sometimes
confused with a plant
• I am usually
multicellular
• I reproduce using
spores
Archaebacteria
• I am prokaryotic
• I live in harsh
conditions (salt lakes,
hot springs and
animal guts)
• I am a heterotroph
• I do have a cell wall,
but it is different from
my cousins the
Eubacteria
Animalia
• I am multicellular
• I usually reproduce
sexually
• My cells don’t have
walls
• I can fly, swim, walk
or run
8Da
Classifying animals
•There are six commonly recognized
Kingdoms
– Eubacteria, Archaebacteria, Protista, Fungi,
Plantae and Animalia
The animal kingdom can be split, further,
into two main groups:
• animals with backbones (vertebrates)
• animals without backbones (invertebrates).
Phylum
• There are more than 30 phyla in
the animal kingdom.
• All but one of these phyla are
invertebrates
• We belong to the one phyla that
has vertebrates (Phylum
Chordata)
Characteristics of all Animals
• Heterotrophic (ingest and digest food)
• Multicellular and some have specialized tissues
and organs
• Cells lack cell walls.
Most reproduce sexually and produce an embryo.
Classification…
Organisms are classified based on several
criteria…
1. Level of body organisation
2. Number of body layers
3. Symmetry
4. Body cavities
5. Movement
6. Reproduction
7. Digestion
1. Level of body organisation
• Are the cells organised into tissues or not?
• Are the tissues organised into organs or
not?
• Are organs organised into organ systems?
2. Number of body layers
• Two layers: Endo and Ectoderm
• Three layers: Endo, Ecto and Mesoderm
Mesoderm gives rise to tissues and
structures including bone, cartilage and
muscle
3. Symmetry
• Asymmetry: Irregular shape
• Radial:
• Bilateral: Each half is
a mirror image of the
other.
4. Body cavities
• Coelom: Fluid filled
space inside the body (a
body cavity)
• Acoelomate: No coelom
• Pseudocoelomate:
Partially formed (not
complete)
• Coelomate: True body
cavity completely lined
with mesoderm
5. Movement
• Sessile: Not able to move around
– May have been able to at one point in
development
• Motile: Able to move
6.
Reproduction
• Asexual: Offspring from single parent
• Sexual: Offspring from two parents
7. Digestion
• Sac-like: Mouth used for both intake of
nutrients and exit of wastes
• Tube-like: Separate openings for food
intake and waste exit (Mouth and anus)
The Invertebrates…
• Can you think of what organisms might be
included in the invertebrate group???
• Of the approximately 30 phylum of
invertebrates there are 6 you should
know…
The Simplest Animals
Phylum Porifera (Sponges):
Once thought to be plants
Cells are not arranged into specialized
tissues or organs.
No nervous system or brain
No muscle tissue – No movement
Rely on water flow for
nutrients which are
absorbed through pores
in their outer walls
http://www.ucmp.berkeley.edu/porifera/porifera.html
8Da
Invertebrates
(5 other phyla)
jellyfish
arthropods
echinoderms
Annelida
molluscs
cnidarians
(segmented
worms
Your Task
• Groups of 4 or 5
• Become experts, in your expert groups, on
your chosen phyla of invertebrates.
• Be prepared to teach others in your home
group all about your phyla.
Plenary
1. What distinguishes invertebrates from other
organisms?
2. What are the different characteristics used to
classify invertebrates?
3. What are the six phyla of invertebrates?
4. Tell me three things you learned in this lesson.
5. Tell me two things you already knew before
this lesson?
6. What is one thing you would like to know more
about? How can you find out?
Invertebrates Continued…
Today you will teach the members
of your home group all about your
phyla of invertebrates
Your task…
• Get together with your expert group to
review your phyla. (5 min)
• Get back into your home groups and teach
about your phyla (35 min). Make sure you
can answer questions about your phyla.
• As a group, answer the questions on your
handout. Discuss your answers and come
to a consensus about the answers
Phylum Cnidaria
• Exhibits radial symmetry.
• Cells organized into tissues.
• E.g., hydrozoans, jellyfish, sea
anemones, sea fans and corals.
Phylum Cnidaria
Two Main Cell Layers
1.
Ectoderm
• Covers outer body surfaces.
• Some have muscle fibers or nerve nets which allows it to
react to environmental stimuli.
2.
Endoderm
• Covers inner body surfaces.
**
Mesoglea:
• A jelly-like layer between ectoderm and gastroderm.
Phylum Cnidaria
• All cnidarians have stinging structures
within their tentacles.
• Toxic substances paralyze prey.
• Mouth/anus leads to gastrovascular
cavity.
• Where digestion, circulation and gas
exchange occur.
Phylum Cnidaria
• Lifecycle alternates between asexual sessile
polyps and sexual free-swimming medusas.
Phylum Cnidaria
Portuguese Man-of-War
• Tentacles may be up to 55 m in length.
Annelida and Mollusca
Body Plan
• Exhibits bilateral symmetry.
• Each half is a mirror image of the other.
• Dorsal: BACK
• Ventral: FRONT
Body Plan
• Cephalization (Position of nervous
structures).
• Sense organs and nerve cells concentrate at
anterior end.
• Bilaterally symmetrical animals move through
environment with anterior end forward.
• Coelom (fluid-filled body
cavity).
Ectoderm
Mesoderm
Coelom
Endoderm
Phylum Annelida
“Segmented Worms”
• Live in marine, freshwater and terrestrial
environments.
• Segmented bodies and a coelom.
• Segmentation allows for larger growth and
enhanced locomotion.
•
•
Phylum Mollusca
“Animals with a Shell”
• Includes snails, slugs,
clams, squids and
octopuses.
• Moist, muscular body
without a skeleton.
All Mollusks
• Have a…
– Complete digestive tract
– Body cavity (coelom)
– Bilateral symmetry for at least part
of their lives
• They have primitive brains and
can sense their environment
using sense organs located on
top of their head.
Phylum Mollusca
Body Plan
1. Muscular Foot
• Locomotion and feeding.
2.
Mantle
• Tissue that covers gills and secretes
shell.
3.
Visceral mass
• Internal Organs.
Phylum Mollusca
Class Bivalva
• Includes clams, oysters, scallops, mussels
and other shellfish.
• Flexible hinge connects
two shells.
• Have no head
• They don’t move much
• Filter feed
Phylum Mollusca
Class Gastropoda
• Includes snails and slugs.
• Use foot for locomotion.
• Respiration through gills and
moist skin.
• Name means
“stomach footed”
Phylum Mollusca
Class Cephalopoda
• Includes squids, octopuses and
nautilus.
• Shell reduced to an internal rod.
– Improves movement.
• Cephalopoda means ‘head
footed’
• Most complex mollusks
• Arms with suckers
• Sexual reproduction
Phylum Echinodermata
“Radially Symmetrical Marine Animals”
• Includes sea stars, sea urchins, sand dollars and
sea cucumbers.
• Larvae:
Bilateral Symmetry
• Adults:
Radial Symmetry (5 similar body
segments = pentamerous)
• Have an endoskeleton (internal skeleton) with
spiny projections.
• Water vascular system:
Phylum Echinodermata
Phylum Arthropoda
“Animals with an Exoskeleton”
• 1, 170, 000 species (mostly insects).
• Segmented bodies, exoskeleton (external
skeleton), jointed legs and blood cavity.
• Exoskeleton composed of chitin:
• Non-Living Material
• Jointed Appendages
• Outside skeleton protects muscles, organs and
blood vessels.
Joint-Legged Animals
Phylum Arthropoda
• As arthropods grow, they molt or shed
exoskeleton and grow a new one.
•
Respiration
• Gills evolved in aquatic arthropods.
• Tracheae developed in terrestrial arthropods.
•
Circulation
• Open circulatory system.
• Blood cavity directly bathes internal organs.
• Nervous System: Simple to complex
• Digestive System made of three parts:
– Foregut – mouth to esophagus
– Midgut - stomach
– Hindgut – intestine to anus
• Reproduction:Sexual
Phylum Arthropoda
Class Arachnida
• Includes scorpions, spiders, mites and
ticks.
• Cephalothorax: head fuses to thorax.
• 4 pairs of legs
Phylum Arthropoda
Class Crustacea
• Includes shrimp, lobsters, crayfish and
crabs.
• Three body segments:
• Head, Thorax and Abdomen
• Paired appendages attach to each segment.
• Two pair of antennae
• Three pair of feeding appendages
• Respiration: Gills
Phylum Arthropoda
Class Insecta
• 1.5 million species.
• Three body segments:
• Head, Thorax and Abdomen
•
•
•
•
Antennae on head sense environment.
Three pairs of walking legs on thorax.
May be one or two pairs of wings
Respiration:
• Air sacs and trachea that extend from external
openings to tissues.
Phylum Arthropoda
• Flying Insects: Two pairs of stiff wings
attached to thorax.
• Flies: One pair of wings.
• Beetles: Front wings form hardened wing
covers.
Phylum Arthropoda
Plenary…
• Discuss answers to questions as a class.
Home Work…
• For each phylum we have learnt about,
describe how their structure is adapted to
their habitat (Hint: pg 416, 427, 441)
• What main characteristics are used to
classify animals into different phyla?
• Turn to pg 441. Do the classifying
Invertebrates activity.
• Turn to pg 445. Do question 25
H/W Finish answering questions on handout
Worm-like Animals
Phylum Platyhelminthes, Phylum Nematoda, Phylum Nematoda
and Phylum Annelida
Body Plan
• Exhibits bilateral symmetry.
• Each half is a mirror image of the other.
• Dorsal:
• Ventral:
Body Plan
• Cephalization.
• Sense organs and nerve cells concentrate at
anterior end.
• Bilaterally symmetrical animals move through
environment with anterior end forward.
• Coelom (fluid-filled body cavity).
Phylum Platyhelminthes
“The Flatworms”
• No coelom due to flattened body.
• Branched gastrovascular cavity increases
surface area for digestion.
• Many are marine parasites.
Phylum Platyhelminthes
Class Turbellaria
• Predators of scavengers
• Marine and freshwater species.
Class Trematoda
• Parasitic flatworms (blood flukes).
• Sucker attaches fluke to host.
• Can cause serious disease in
humans
Phylum Platyhelminthes
Class Cestoda
• Tapeworms (eat the food in our digestive
tract)
• Flat body composed of many sections.
• Suckers and hooks attach tapeworm to
intestines.
Phylum Nematoda
“The Roundworms”
• Have a complete digestive tract
• Scavengers in soil and found at bottoms of
lakes and ponds.
• Some are parasites
• Trichinosis
• 10,000 species identified.
• Microscopic to 1 m in
length.
Phylum Annelida
“Segmented Worms”
• Live in marine, freshwater and terrestrial
environments.
• Segmented bodies and a coelom.
• Segmentation allows for larger growth and
enhanced locomotion.
• More advanced brain
• More advanced digestive
system
Sources
• http://www.underwater.com.au/image.php/id/5254/
• http://www.stanford.edu/class/humbio103/ParaSites2006
/Taenia_saginata/Introduction.html
• http://www.mbari.org/benthic/other.html
• http://www.solaster-mb.org/mb/platyhelminthes.htm
• http://www.scienceclarified.com/Oi-Ph/Parasites.html
• http://www.seaslugforum.net/showall.cfm?base=flatworm
• http://www.onset.unsw.edu.au/issue7/Tapeworm.bmp
• http://www.cbu.edu/~seisen/PlatyhelminthesReview.htm
• http://www.levitated.net/notes/ECC/
• http://www.bu.edu/lernet/GK12/eric/index.html
Joint-Legged Animals
Phylum Arthropoda
“Animals with an Exoskeleton”
• 1, 170, 000 species (mostly insects).
• Segmented bodies, exoskeleton (external
skeleton), jointed legs and blood cavity.
• Exoskeleton composed of chitin:
• Non living
• Thick and heavy or thin and light
• Provides protection
Phylum Arthropoda
• As arthropods grow, they moult or shed
exoskeleton and grow a new one.
• Respiration
• Gills evolved in aquatic arthropods.
• Tracheae developed in terrestrial arthropods.
• Circulation
• Open circulatory system.
• Blood cavity directly bathes internal organs.
Phylum Arthropoda
Class Arachnida
• Includes scorpions, spiders, mites and
ticks.
• Cephalothorax: head fuses to thorax.
• 4 pairs of legs:
• The first pair may serve sensory function
• Used for feeding, defense and locomotion
Phylum Arthropoda
Class Crustacea
• Includes shrimp, lobsters, crayfish and
crabs.
• Three body segments:
• Head, Thorax, Abdomen
• Paired appendages attach to each
segment.
• Two pairs of antennae
• Feeding appendages
• Appendages for moving
Phylum Arthropoda
• Feathered gills increase surface area for
gas exchange.
Phylum Arthropoda
Class Insecta
• 1.5 million species.
• Three body segments:
• Head, Thorax, Abdomen
• Antennae on head sense environment.
• Three pairs of walking legs on thorax.
• Respiration:
• Air sacs and trachea that extend from external
openings to tissues.
Phylum Arthropoda
• Flying Insects: Two pairs of stiff wings
attached to thorax.
• Flies: One pair of wings.
• Beetles: Front wings form hardened wing
covers.
Phylum Arthropoda
Growth and Development:
• Body plan stays the same as the animal
develops.
• Metamorphosis
• Body plan changes as the animal develops.
• Change in diet lowers competition between
larvae and adults.
Phylum Arthropoda
•
Complete
metamorphosis in ants.
Incomplete metamorphosis in
dragonfly.
Phylum Arthropoda
Class Diplopoda and Chilopoda
• Diplopods are millipedes.
– Each body segment has two pairs of legs.
• Chilopods are centipedes.
– Each body segment has one pair of legs.
Both have up to 100 pairs of legs.
Phylum Arthropoda
Sources
• http://www.afsc.noaa.gov/RACE/media/photo_g
allery/invert_files/Sidestriped_shrimp.htm
• http://quinnell.us/personal/carlin/journal/lobster.h
tml
• http://www.teridanielsbooks.com/States/Hawaii.h
tm
• http://www.foodsubs.com/Shelfishcrab.htm
• http://www.treknature.com/gallery/North_Americ
a/photo60786.html
• http://www.amonline.net.au/insects/insects/meta
morphosis.htm#insect
Plenary