Transcript Kingdom Animalia

Kingdom Animalia
Characteristics
1.
2.
3.
4.
5.
6.
Heterotrophic (ingest their food)
Eukaryotic
Multicellular (made of many cells)
Movement
Sexual reproduction
Absence of a cell wall
7. Blastula (hollow ball of cells) formation
(except in sponges)
Gives rise to three tissues
3 tissue layers
Ectoderm
Outer skin, nervous,
sensory
Endoderm
Digestive and
respiratory structures
Mesoderm
Skeleton, muscles,
circulatory, reproductive
8. Tissues (all animals except sponges)
Body Symmetry
• Asymmetrical: irregular in shape; sponge
Radial symmetry: body parts
arranged around a central axis
• Coral, jellyfish
Bilateral symmetry: distinct left and
right halves
• Butterfly
Most have anterior concentration of
sensory structures (cephalization)
Internal Body Cavity
A. Acoelomate: No body cavity.
Example: flatworm
B. Pseudocoelomate: body cavity
between mesoderm and endoderm
• Example: roundworm
C. Coelomate: fluid filled space between
body wall and digestive tract, protects organs
during movement
• Example: earthworm, human
Animal Body Systems
A. Digestion:
• Sponges digest intracellularly while all
other animals digest extracellularly
• Hydra has a gut with one opening, while
more advanced animals have 2
B. Respiration
• Simple animals (sponges) use diffusion
• Some aquatic and terrestrial animals use
gills (must stay moist)
• Other organs, such as lungs, have evolved
Which are more efficient: gills or
lungs?
C. Circulation
• Simple animals use diffusion
• Two types of circulatory systems are:
1. Open circulatory system: fluid leaves the
circulatory vessels. Example: clam
2. Closed circulatory system: blood
remains in the circulatory vessels.
Example: earthworm
D. Conduction of Nerve Impulses
• Nerve cells (neurons) are specialized for
carrying electrical impulses
• Found in all animals except sponges
• Simplest arrangement is a nerve net
(hydra)
• A nerve cord and brain with sensory
structures such as eyes are more
advanced
E. Support
•
The skeleton supports the body and
allows for movement
• Muscles contract against the framework
of the skeleton
1. Hydrostatic skeleton – fluid under
pressure in a closed cavity
• Seen in soft-bodied invertebrates such
as the hydra and jellyfish
Worms have hydrostatic skeleton
2. Exoskeleton – rigid, external skeleton
found in arthropods, bivalves
•
Muscles are attached to inside of skeleton,
which protects organs
3. Endoskeleton – embedded inside an
animal, such as the bones within a mammal
F. Excretion – removal of wastes
produce by cellular metabolism
• One toxic waste is ammonia
• Some animals excrete waste through skin
or gills
• Others use kidneys
or other structures
designed to minimize
water loss
Reproductive Strategies
1. Asexual Reproduction – does not involve
the fusion of 2 gametes
2. Sexual reproduction
• Some animals, called hermaphrodites,
have both testes and ovaries.
Examples: slugs, earthworms, some
fish
• External fertilization: aquatic animals
release sperm and eggs near each other
• Internal fertilization: union of sperm and
egg occurs within the female’s body
Invertebrates: more than 95% of
all animal species
Phylogenetic tree
Porifera
Cnidaria Platyhelminthes Annelida
Mollusca
Echinodermata
Nematoda Arthropoda
Chordata
RADIAL
DUETEROSTOMES
PROTOSTOMES
NO TISSUES
I. Phylum Porifera
Sponges
Sponges
•
•
•
•
asymmetrical
filter-feeders, feed intracellularly
sessile (live attached to an object)
Reproduce asexually or sexually (can
have separate sexes or be
hermaphrodites)
II. Phylum Cnidaria
• Jellyfish, hydra, Portuguese man-of-war,
coral, sea anemone
Evolutionary milestone is:
• Tissues
• Extracellular digestion in a gastrovascular
cavity
• Tentacles with stinging cells
• Two body forms are medusa and polyp
Examples
Moon
jellyfish
Is this a
polyp or
medusa?
Hydra
Portuguese man-of-war
Close up view of tentacles
Coral
A hydra feeding
Box jellyfish – can be very
deadly
III. Phylum Platyhelminthes
• Evolutionary milestone is bilateral symmetry
A. Commonly known as flatworms
B. Examples include free-living planarian and
parasitic tapeworms
C. Oxygen, carbon dioxide, digested food all
move by diffusion
Most have anterior concentration of
sensory structures (cephalization)
D. Tapeworm (parasitic) can be
avoided by properly cooking food
Planarian is free-living
IV. Phylum Nematoda
• Roundworms
• Evolutionary milestone is body cavity
(pseudocoelom)
• Examples include:
• Heartworms in dogs and cats
• Hookworms
• Free living roundworms
Characteristics include a one-way digestive tract
(2 openings)
Hookworms are acquired by walking
barefoot in contaminated soil
V. Phylum Mollusca
Mollusk Body Plan
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Types of Mollusks
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Cephalopods
-Many have an ink sac and are capable of
expelling ink to confuse predators
-Octopuses and
squids can change
color using pouches
of pigment called
chromatophores
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VI. Phylum Annelida
• Segmented worms
brain
blood vessels
hearts
muscle
mouth
digestive tract
segment
nerve cord
Characteristics
• Cerebral ganglion, or primitive brain in an
anterior segment
• Coelom, or true body cavity
• Closed circulatory system
• excretory structures called nephridia
• Earthworms are hermaphroditic
-Clitellum secretes mucus that holds the
worms together during mating
-Also secretes a
mucus cocoon, in
which the fertilized
egg develops
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Marine worms
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Types
A. Marine worms; largest group
• may burrow, or live in protective tubes
B. Earthworms
Describe the two useful functions earthworms
provide as they eat soil.
1. Aerate the soil, allowing air and water to
penetrate
2. Their castings (wastes) act as fertilizer
C. Leeches
• have suckers at both ends of body
• most are predators or scavengers, but
some are parasites
VII. Phylum Arthropoda
• Evolutionary Milestone is Jointed
appendages
VIII. Echinodermata
VIII. Phylum Echinodermata
A sea star, regenerating 2 arms.
This will take over a year!
Sand dollars
Sea Urchins
Evolutionary
milestone is
deuterostome
embryo
development
Characteristics of Echinoderms
A. Live in marine environments
B. Have an endoskeleton, covered by
a thin epidermis.
C. Radial Symmetry (bilateral as
larvae)