bi 101: invertebrate animals - linn–benton community...
TRANSCRIPT
6/3/2013
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BI 101: Invertebrate Animals Announcements
• Quiz #6 Friday
– Plants: Gymnosperms & Angiosperms
• Don’t forget the prelab– just the front page
• I have another lab to substitute the one in the packet--- food web of the compost pile!
– Bring compost!
Classification
Bacteria Archaea Eukarya
Bacteria Archaea Protista Plantae Fungi Animalia
Monera Protista Plantae Fungi Animalia
The three-domains
The six-kingdom system
The traditional five-kingdom system
Alveolates
Euglenozoa
(Forams and Radiolarians) Rhizarians
CHLOROPHYTA
Stramenopile Rhodophyta
AMOEBOZOANS
Animal Cell
Fungus Cell
Evidence indicates that animals evolved from choanoflagellates (protists) ~ 570 mya
• Single cells • Often clonal • Heterotroph • No
specialization or coodination between cells
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What are some characteristics animals share? List as many as you
can think of.
Discuss this in your groups
What is the difference between vertebrates and invertebrates?
Animal Classification
1. DNA sequencing
2. Body Symmetry
3. Presence or absence of body cavity
4. Embyonic Development
Symmetry
Body Cavity
Most bilateral animals have body cavities –Body cavities are fluid-filled cavities
between the digestive tube and the outer body wall
– Functions: • skeleton, providing support for the body and a
framework against which muscles can act
• protective buffer between the internal organs and the outside world
• They can allow organs to move independently of the body wall
Fig. 25-4a, p. 405
epidermis gut
cavity
A No coelom
(acoelomate animal)
organs packed between
gut and body wall
Body Cavity?
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Fig. 25-4b, p. 405
epidermis gut
cavity
B Pseudocoel
(pseudocoelomate animal) unlined body cavity around gut
Body Cavity?
Fig. 25-4c, p. 405
gut
cavity epidermis
C Coelom
(coelomate animal) body cavity with a lining (dark
blue) derived from mesoderm
Body Cavity?
Embryonic Development Blastopore forms
mouth first
Blastopore forms anus first
Protostomes
Deuterostomes
Porifora - sponges
• Sessile (Larva motile)
• No true tissues or organs
• Exhibit asymmetry or radial symmetry
• Filter feeders
epithelial
cell
amoeboid
cell
pore
spicules
pore cell
collar cell
(water flow)
(water flow out
of the sponge)
(water flow into
the sponge)
Sponge Anatomy
Fig. 23-5
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Sponge filtration/feeding
http://www.youtube.com/watch?v=T7E1rq7zHLc&feature=player_embedded
Collar Cell
Collar Cell
http://www.youtube.com/watch?v=29W77870BgE&list=PLVN5247pOBYcE1Mn_pWHIL9l0sMIx19TI
Sponges for Breast Cancer Research!
• The artificial component called eribulin mesylate imitates an element found in sponges.
• It can check cell division, which is a reason of cells to self-damage.
• http://www.topnews.com.sg/content/22106-marine-sponge-probable-treatment-breast-cancer
Cnidaria – Sea Anemone
• Radial symmetry
• Two tissue layers
• Filled with water– supports body
• Nerve net
• Nematocysts -stinging organelles that release toxins
trigger
filament
trigger
nuclei
(b) Cnidocytes
Cnidarian Weaponry: The Cnidocyte
Fig. 23-8
Coral is a mutualism between photosynthetic dinoflagellates (protist) and a cniderian (animal)
• Algae in coral called zooxanthelle
Cnidaria: Symbiosis
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Cnideria video
Colonial polyps secrete a hard external skeleton of calcium carbonate
The skeleton remains after the polyp dies
New polyps build on the skeletal remnants of earlier generations
In many coral species polyps form colonies
Platyhelminthes - flatworms
• Bilateral symmetry
• 3 tissue layers
• Cephalization (nerve mass)
• True organs and organ systems
• Aceolomate (no body cavity)
• Parasitic forms but some free living
Evolved ~500 mya
Mollusca
Characteristics:
• bilateral symmetry
• Coelomates- true body cavity
• Unsegmented
• aquatic & terrestrial
• possess all organ systems
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Mollusca Diversity 2nd most diverse animal group: 93,000 species
Gastropods 80% of mollusk species • Snails • Slugs • Nudibranchs
Bivalves Aquatic • Clams • Mussels
Cephalopods Most neurologically advanced Marine predators • Octopus • Squid • Cuttlefish
Nudibranchs • 3,000 described species
• Snails without a shell
• Unique lifestyle and defense mechanisms
Glaucus atlanticus consumes ‘man of war’ jellyfish and puts the nematocytes on its own back!
Elysia– the photosynthetic animal (video)
Nudibranchs
The Blue Dragon, Pteraeolidia ianthina, has a symbiosis with dinoflagellates. It also steals the armed tentacles of a sea anemone, a Cniderian, for defense and combat!
Fig. 32-8Coelom
Body covering
(from ectoderm)
Digestive tract
(from endoderm)
Tissue layerlining coelomand suspendinginternal organs(from mesoderm)
(a) Coelomate
Body covering
(from ectoderm)
Pseudocoelom
Digestive tract(from endoderm)
Muscle layer(frommesoderm)
(b) Pseudocoelomate
Body covering(from ectoderm) Tissue-
filled region(frommesoderm)
Wall of digestive cavity(from endoderm)
(c) Acoelomate
Annelida - segmented worms
• Segmented body
• Bilateral symmetry
• 3 tissue layers
• Coelom (fully enclosed body cavity)
• Organ systems are more fully developed
• Decomposers and Parasites
Annelida - segmented worms
• Class: Polychaetes – Each segment with many hairlike
chetae – 12,000 species – Mostly marine
• Class: Clitellata – Earthworms - Oligochaete
10,000 species Terrestrial Decomposers
– Leeches – Hirudinea 700 species Predators or parasites Most freshwater
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Arthropoda– Earth’s most diverse phylum
Billions of species!
Major groups: • Crustaceans
• Myriopods
• Arachnids
• Hexapods
Arthropoda Characteristics
1. Exoskeleton= External skeleton
2. Specialized body segments
3. Jointed appendages
4. Bilateral symmetry
5. True coelom (body cavity)
Trachea
Arthropoda respiratory
system:
Example: Grasshopper
• Spiracles: pores in exoskeleton
• Trachea: connect to spiracles, carry oxygen to the body cells
Arthropoda respiratory
system: Arthropoda respiratory system
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Arthropod Phylogeny
Chelicerata
8 legs
• Arachnids – spiders,
–Mites
– Ticks
– scorpions
• Horseshoe crabs
• Pseudoscorpians
Arthropod Phylogeny
Crustaceans
Rolly pollies– Isopods
Lobsters
Crayfish
Crabs
Shrimp
Krill
Baracles
Arthropod Phylogeny
Myripoda
• Class: Symphyta
• Class: Chilopoda (centipedes)
• Class: Diplopoda (millipeds)
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Arthropod Phylogeny
Hexapoda:
Reduction in body segments to 3
Reduction in legs to 6
Co
llem
bo
la
Insecta Pro
tura
Dip
lura
Arthropod Phylogeny
Hexapoda:
Reduction in body segments to 3
Reduction in legs to 6
Co
llem
bo
la
Pro
tura
Dip
lura
Insecta: mouthparts
outside head capsule
Arc
hae
gnat
ha
Slve
rfis
h:
Thys
anau
ra
Wings!
Figure 23-19 Segments are fused and specialized in insects
abdomen
thorax
head
antennae
compound eye
mouth parts
wing
Specializations for Feeding
Grasshoppers (a) – mouth has
numerous manipulating and
shearing parts for eating
vegetation.
Flies (b) – has a labium mouth
part that has a sponge like end for
absorbing nutrients from moist
foods.
Butterflies & Moths (c) – mouth
part is a tube like maxilla for
sucking up nectar from flowers.
Mosquitoes (d) – have a stylus
for piercing their prey to draw
blood like a hypodermic needle.
Announcements
• Final exam next Monday 1-3pm
• Study guide up on website
• Final quiz this Friday: invertebrate animals!
• Study sessions?
Insect Development
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Discussion
• Why might it be advantageous for insects to have complete metamorphosis?
Nematoda - Round worms Fig. 32-8
CoelomBody covering
(from ectoderm)
Digestive tract
(from endoderm)
Tissue layerlining coelomand suspendinginternal organs(from mesoderm)
(a) Coelomate
Body covering
(from ectoderm)
Pseudocoelom
Digestive tract(from endoderm)
Muscle layer(frommesoderm)
(b) Pseudocoelomate
Body covering(from ectoderm) Tissue-
filled region(frommesoderm)
Wall of digestive cavity(from endoderm)
(c) Acoelomate
• Exoskeleton (molts)– body coved in a thick cuticle
• Psuedocoelom (false body cavity)
• Bilateral worms
• 3 tissue layers
• Unsegmented
• Parasitic (50%)
and free-living (50%)
25,000 species
A Freshwater Nematode
Fig. 23-25
ovary vagina mouth cuticle eggs
anterior
end
posterior
end
intestine
Discussion questions
1. How do earthworms differ from tapeworms and planarians?
2. How do earthworms differ from nematodes?
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6,000 species
Includes sand dollars, sea urchins, sea stars, sea cucumbers, and sea lilies
Phylum Echinodermata
Echinodermata characteristics 1. Deuterostomes
Echinodermata characteristics 2. Larvae exhibit bilateral symmetry; adults show radial symmetry
Echinodermata characteristics 3. Endoskeleton (internal skeleton) that sends projections through the skin
Composed of calcareous plates or ossicles
Echinodermata characteristics
4. Water vascular system:
Food and waste
transport
Respiration
Locomotion
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Discussion question
• How do sea urchins and sea stars differ from sea anemones and coral?
VS
Phylum Chordata
Contains both vertebrates AND invertebrates!
All Chordates share four characteristics: 1. Dorsal nerve cord
2. Notochord (Primitive skeleton)
3. Pharyngeal gill slits
4. Post-anal tail
Animal Diversity Ancestral Derived
Radial
0, 2
1
Acoelomate, Pseudocoelomate
Protostome
Symmetry
# of tissue layers
# gut openings
Type of coelom
Type of development
Bilateral
3
2
Eucoelomate
Deuterostome
Animal Diversity Ancestral Derived
Radial
0, 2
1
Acoelomate, Pseudocoelomate
Protostome
Symmetry
# of tissue layers
# gut openings
Type of coelom
Type of development
Bilateral
3
2
Eucoelomate
Deuterostome