Download I. Animal Characteristics - Parkway C-2

Biology Notes for Unit #5: Kingdom Animalia (The Invertebrates)
 Kingdom Animalia is thought to have evolved from… ______________________________
I. Animal Characteristics
1. Multicellular - _____________________
2. Eukaryotic - ___________________________________________________________________________
3. Heterotrophic – ____________________________
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herbivores – _________________________
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carnivores - _________________________
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omnivores - _________________________
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parasites - __________________________
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filter feeders - ______________________
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saprotrophs/detrivores – _______________
4. Lack cell walls
5. Specialization (specialized cells for all animals and specialized tissues for most animals)

How are specialized cells advantageous/beneficial to an animal? ________________________________

How are specialized cells disadvantageous to an animal? ______________________________________
6. Animals store their extra glucose in large molecules termed… ____________________________________
7. Sexual and/or Asexual Reproduction – Diploid/somatic (2n) cells are always dominant (greater in #) to the
haploid/sex (n) cells.
8. All animals undergo embryonic development starting w/a zygote, then through the blastula & gastrula stages.
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Explanation of the Phylogenetic Tree of Animal Characteristics
1. Symmetry – The arrangement of body parts around a central axis.
a) Asymmetry – __________________________________________
b) Radial Symmetry – Can be divided into equal parts at many planes along the central axis (like a pizza)
- Found predominately in sessile (low or no mobility) animal species.
- Radially symmetrical animals possess oral (mouth) and aboral (away from mouth) regions.
? Why is it advantageous for sessile organisms to have radial symmetry? _____________________________
__________________________________________________________________________________
c) Bilateral Symmetry –
Anterior Ventral -
Posterior Dorsal –
 Cephalization – The concentration of nerves and sensory tissue/organs at
the anterior portion of bilateral organisms (possesses a head).
Label the body regions on the squirrel 
2. Embryological Development
a) Fertilization  Egg (n) + Sperm (n) = Zygote (2n)
Zygote divides & grows in # of cells by the process of somatic cell reproduction (mitosis) into 2-4-8-16-32-64 cells.
b) Morula – The 64-cells stage of development that takes the shape of a solid ball.
c) Blastula – The 64-cells stage of development that takes the shape of a hollow ball (like a soccer ball with air).
d) Gastrula – A growing (128+ cells) and indented (like a deflated soccer ball) hollow group of cells (former blastula).
The gastrula stage of development triggers the beginning of specialization. Genes are being turned on
or off in the developing animal to form three germ layers. Germ layers and general descriptions below 
 Endoderm – Will develop into the tissues/organs of the digestive (food & water) and respiratory (air) tracts.
 Ectoderm – Will develop into the tissues/organs of body covering (feathers, fur, claws, skin) & nervous system.
 Mesoderm – Will develop into the tissues/organs of muscles and skeleton (not found in Porifera or Cnidaria).
???
Advantages/Disadvantages of body plans
Slides of embryology= Kat
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1 _______________________________________________
2 _____________________________________
3 _____________________________________
4 _____________________________________
5 _____________________________________
6 _____________________________________
7 _____________________________________
3. Body Cavity – Fluid filled spaces that lie between the digestive tract and the body wall. Body cavities provide a
space for organs to grow and move without being twisted or crushed during body movement. Body
cavities, being lined by membranes, isolates infection & specific organ functions.
Acoelomates – Animals lacking a body cavity (Porifera – sponges, Cnidaria – jellyfish, Platyhelminthes – flatworms).
Pseudocoelomates – Animals with a cavity located between the mesoderm & endoderm (Nematodes - roundworms).
Eucoelomates – Animals that have a body cavity that develops within the mesoderm (all other animals).
* Create a color key and color the germ layers and body cavity in all 3 diagrams below
Endoderm
Mesoderm
Ectoderm
Digestive
Coelom
Tube/Gut
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4. Coelom Formation
a) Protostomes (1st mouth) – Blastopore (area of indent of gastrula) becomes the mouth (Cnidaria→Arthropods).
b) Deuterostomes (2nd mouth) – Blastopore becomes the anus (Echinoderms and Chordates).

Color the developing organisms using the colors indicated below.
)
6. Development
 Direct development – Offspring are smaller versions of an adult.
Examples - ____________________________________
 Indirect development (metamorphosis) – Offspring undergo
physical changes before becoming an adult.
Incomplete metamorphosis (egg→larvae/nymph→adult) –
Larvae will have a similar body form to the adult, but
will lack sexual organs & adult structures (like wings).
Complete metamorphosis (egg→larvae→pupa→adult) –
The developing organism (larvae) will undergo dramatic
changes during the pupa stage and will differ in shape
and diet from the adult.
? How is metamorphosis an advantageous adaptation?
___________________________________________
___________________________________________
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II. Invertebrate Phyla
Phylogenetic Tree of Animal Characteristics (with representative phyla)
____________________
(Porifera – sponges)
_____________________
(Cnidaria - jellyfish)
_____________________
(Platyhelminthes)
_____________________
(Nematodes – roundworms)
__________________
Kingdom
____________________
Symmetry
_____________________
(Mollusks, Annelids, Arthropods
Echinoderms, Chordates)
Body Cavity
______________________
(Cnidaria→Arthropods)
_______________________
(Echinoderms & Chordates
Coelom Development
 Invertebrates lack a vertebral column/backbone. There are 35 invertebrate phyla. Eight of the most common
invertebrate phyla will be discussed in some detail. Make up more than 95% of all animal species.
1. Phylum Porifera (“pore bearer”, Examples: sponges – 5,100+ species)
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Key evolutionary advance = ___________________________
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Asymmetrical acoelomates
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Possess no tissues or organs.
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Reproduce sexually or asexually
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Hydrostatic skeleton- ___________________________________________________________________
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Possess high regeneration (regrowth) abilities.
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Most live in marine environments. The multi-colored sponges can live alone or in colonies.
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Sessile as an adult and mobile as a larvae. The larvae are morphologically (shaped) different from the adult.

Sponges benefit man as a commercial sponge (scrubber), a producer of antibiotics that kill bacteria , chemicals
affecting arthritis and some cancers. Sponges also serve as habitats for small invertebrates.
2. Phylum Cnidaria (Examples: sea anenomes, coral, jellyfish, hydra, sea fans – 11,000+ species)
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Key evolutionary advance = ___________________________________________________
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Cnidarians possess radial symmetry with tissues, and may live alone (jellyfish) or in colonies (coral)
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Acoelomate with two germ layers (ectoderm & endoderm) which surrounds the mesoglea (jelly-like substance).
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Possess a nerve net to respond to stimuli in their environment like light, movement, touch, and gravity.
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All Cnidarians live in water, most are marine. Many have tentacles or arms with cnidocytes (stinging cells).
Cnidocytes possess Cnydocysts (stingers) to capture live prey, making cnidarians carnivores. Some Cnidarians
(corals) live symbiotically with photo-synthetic organisms to obtain energy in nutrient poor waters.
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The very thin Cnidarians move water, nutrients, and waste products through their body via diffusion.
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They have a hydrostatic skeleton
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Reproduction may be sexual or asexual.
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Life forms include one or both of the following stages:
Polyp – sessile stage, mouth on top (coral)
Medusa – mobile stage, mouth on bottom (jellyfish)
3. Phylum Platyhelminthes (“flatworms”, Examples: planarians, flukes, and tapeworms.– 20,000+ species)
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Key evolutionary advance = ______________________________________________________
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Flatworms possess bilateral symmetry, cephalization, and organs.
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Flatworms are unsegmented acoelomates with all three germ layers.
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Most are parasitic and/or carnivores (flukes & tapeworms).
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
Without circulatory or respiratory systems, flatworms move nutrients, water, oxygen, and waste via diffusion and
an extensive digestive cavity. Flatworms do possess primitive systems including a one-way digestive tract with a
mouth and an anus.
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They have a hydrostatic skeleton
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Platyhelminthes possess a primitive nervous system that detects movement, light, food, and chemicals.
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Most flatworms are hermaphrodites, possessing both male & female sexual structures. Some reproduce asexually.
4. Phylum Nematoda (“roundworms”, Examples: human parasites Trichnella, Ascaris, hookworms, & pinworms. Also
C. elegans used extensively in scientific research – 12,000+ species)
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Key evolutionary advance = _____________________________________________________________
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Nematodes are unsegmented roundworms which taper at their ends, and exhibit cephalization.
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Nematodes possess bilateral symmetry, a hydrostatic skeleton and are pseudocoelomates.
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Many are parasitic, others are free-living carnivores in soil, mud, fresh and salt water ecosystems.
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Nematodes show separate sexes with sexual and asexual reproduction occurring in different species.
5. Phylum Mollusca (“soft-bodied” with one or more shells - 110,000+ species)
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Key evolutionary advance = _______________________________________________________________
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Mollusks are the least advanced of the eucoelomates, possess bilateral symmetry, have a hydrostatic or
exoskeleton skeleton, and are protostomes.
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All
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3 classes of Mollusca
 Gastropods (snail, slug) – Use a muscular foot to crawl, their mantle often secretes a single, hard shell. They
are herbivores.
 Bivalves (oyster, clam, scallop) – Secrete a two-part shell w/a hinge. Bivalves filter feed.
 Cephalopods (octopus, squid) – Have a modified mantle cavity to create jet propulsion for rapid movement.

Mollusks possess respiratory, digestive, excretory, reproductive, nervous, and circulatory (open) systems.
mollusks have a basic body plan consisting of three parts:
Head – Contains sense organs
Visceral Mass – Internal organs
Foot – For movement
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Open Circulatory system – A system in which blood is not always contained within blood vessels (veins, arteries, capillaries).
Closed Circulatory system – A system in which blood is contained within blood vessels.
Open Circulatory System
Closed Circulatory System
6. Phylum Annelida (“segmented worms”, Examples: bristle worms, earthworms, and leeches – 12,000+ species)
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Key evolutionary advance = _____________________________
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Annelids are bilaterally symmetrical, have a hydrostatic skeleton,
are eucoelomates, and protostomes.
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All but one annelid species possess bristle-like structures called setae along their ventral region used to move.
7. Phylum Arthropoda (“jointed feet”, Examples: insects, spiders, ticks, crabs, and centipedes - 1 million + species)
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Key evolutionary advance = _____________________ _____________________________
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Arthropods possess bilateral symmetry, are eucolemates, and undergo protostome development.
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Arthropods have segmented bodies with paired appendages attached to each segment. There is much variation
among the arthropods as it pertains to their appendages. Some appendages have increased in size, while others
have decreased in size or been lost over time. Appendages include mouth parts, tails, wings, flippers, claws,
antennae, walking legs, etc.
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Arthropods possess an exoskeleton made of protein and the carbohydrate chitin which serves several functions.
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_______________________________________________________________________
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______________________________________________________________________
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________________________________________________________________________________
Molting – The process of periodically shedding the hard exoskeleton allowing the arthropod to grow.
Molting makes the arthropod susceptible to… ______________________and ___________________.
Insects – Insects possess a distinct head, thorax (chest), and abdomen. Insects possess 1 pair of antennae (touch,
smell, hear), pairs of jointed legs, 1 or 2 pairs of wings (usually 2), and 11 segments on their abdomen.
Entomologist – Scientist who studies insects. 1 million + have been classified, up to 30 million may exist.
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List 3 ways in which insects positively affect humans and 3 ways they negatively affect humans:
Positives
Negatives
1. ________________________________________
1. _____________________________________
2. ________________________________________
2. _____________________________________
3. ________________________________________
3. _____________________________________
 Insects are the most successful animals on the earth. There success comes via their short life span (quick
reproduction and fast adaptation), small size (able to live in any sized habitat), and flight (ability to evade
predators and move to a wide range of habitats).
 Insects communicate in many ways and for a variety of reasons; sound (crickets – talk to potential mates), light
(fireflies signaling potential mates), chemicals (pheromones to signal alarm, attract mates, indicate direction).
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8. Phylum Echinodermata (“spiny-skinned”, Examples: sea stars, sand dollars, sea cucumber & urchins, 6,000+ species)
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Key evolutionary advance = ______________________________________________________________
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Examples include seastar, brittlestar, feather star, sea lily, sand dollar, sea cucumber & sea urchin.
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Echinoderms are mostly marine, eucoelomates, and deuterostomes (blastopore becomes the anus).
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Echinoderms undergo a metamorphosis from a free-swimming, bilaterally symmetrical larvae to a bottom-dwelling
adult with radial symmetry. Most echinoderms have pentaradial symmetry (arms or tentacles in multiples of 5).

Because echinoderm larvae are bilaterally symmetrical, scientists infer that they evolved from bilaterally
symmetrical ancestors. The fossil record also indicates that the early adult forms of the ancient echinoderms
were probably sessile and not free-living as most modern forms are. Scientists infer that radial symmetry in the
adults evolved to adapt to this sessile existence.

Echinoderms possess an endoskeleton (____________ ______________).
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Echinoderms possess no circulatory (blood), respiratory (lungs or gills), or excretory (waste management) systems.
The functions of circulation, respiration, and waste management are performed by the water-vascular system.
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Echinoderms have primitive digestive and nervous systems with no brain or head.

Echinoderms have separate sexes but can reproduce sexually or asexually.
Female sea stars produce up to 200 million eggs in one season. After external fertilization (sperm swims to egg
outside the body) the bilateral, free-swimming larvae settles to the bottom of their water source (ocean, sea).
After 2 years metamorphosis begins. The bilateral larva morphs/changes into a radially symmetrical adult.
Asexual reproduction in sea stars occurs if a sea star is torn apart and contains a piece of the central disk.
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Invertebrate Phyla Compare & Contrast Data Table
Characteristics
Porifera
(Pore Bearer)
Cnidaria
(Stinging Cells)
Platyhelminthes
(Flatworms)
Nematoda
(Round Worms)
Mollusca
(Soft Bodied)
Annelida
(Little Rings)
Arthropoda
(Jointed Feet)
Echinodermata
(Spiny Skinned)

Key Evolutionary
Advance
Multicellularity
Jointed
Appendages
Body Cavity
(true)
Examples
Nutrition
Symmetry
Germ Layers
Carnivores
Parasitic
Parasitic
Detrivore
Sea Stars
Sea Cucumbers
Sand Dollars
Bilateral-Larvae
Asymmetrical
Ectoderm
Ectoderm
Mesoderm
Endoderm
Endoderm
Coelom Type
Detrivore
Exoskeleton
Insects
Spider-Ticks
Lobster-Crabs
Carnivore
Herbivore
Parasitic
Acoelomate
Acoelomate
Absent
Absent
Ectoderm
Mesoderm
Endoderm
Ectoderm
Mesoderm
Endoderm
Pseudocoelomate
Radial-Adult
Ectoderm
Mesoderm
Endoderm
Eucoelomate
Coelom Development
Reproduction:
Asexual
Budding
Fission -splitting
Gemmules
Reproduction:
Sexual
Miscellaneous
High
Regeneration
Polyp – Sessile
Medus – Mobile
Mostly Marine
All aquatic & most
are marine
No Tissues
Mobile larvae Sessile Adult
Internal transport
via diffusion
Hermaphrodite:
Egg & Sperm
Formation
Unsegmented
Separate Sexes
Internal Transport
via diffusion
Tapered Ends
1-way digestion
w/mouth & anus
Unsegmented
Incredibly
numerous in soil
None
None
Regeneration
Segmentation
Most Marine
Molt – Growth
Water Vascular
System – waste,
circulation,
respiraton
Hermaphrodite
Separate Sexes
Foot – Mobility
Head – Senses
Visceral MassOrgans
Open circulatory
Setae – Mobility
Most Common
Gene research use
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