Animals Part I - CCRI Faculty Web
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Transcript Animals Part I - CCRI Faculty Web
Chapter 17
Remember….
D
K
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Kingdom Animalia
General characteristics:
– Heterotrophic
– Locomotion
– Multicellular
– Life cycle where adult is diploid
– Undergoes sexual reproduction and produce an embryo
Characteristics of Animals
Type of body plan
Digestive tracts
Level of organization
Type of body cavity
Type of symmetry
Skeletal system
Reproduction
Respiration
Type of Body Plan
Sac-Plan
– Incomplete digestive
system
– Gastrovascular cavity
Tube-Within-a-Tube Plan
– Complete digestive system
– Inner tube is digestive
system, outer tube is body
wall
– Two openings
Digestive Tracts
Incomplete
One opening
same opening used to take in food and get rid of
wastes
GVC
Complete
Two openings
food is ingested at one end
wastes from digestion passed out of the tract at the
other end
Level of Organization
Cellular
Only composed of cells
Sponges
Tissue
Composed of cells and tissues
Jellyfish
Organ
Composed of cells, tissues, and organs
Us!
Type of Body Cavity
Acoelomate
– Lacks a body cavity
– Tissues packed closely together
Pseudocoelomate
– Body cavity incompletely lined with
mesoderm
– fluid-filled cavity that contains their
organs
– Organs are free within the cavity and
will move around easily when you
manipulate them
Coelomate
– Cavity that contains organs
– Lined with mesoderm
Type of Symmetry
Asymmetrical
– No particular symmetry
Radial Symmetry
– Circular organization
– can be bisected in any plane to produce mirror images
– Sessile
Bilateral Symmetry
– Definite right and left halves
– only a cut down the midline will produce mirror images
Animal skeletons
Can be:
Hydrostatic
Exoskeleton
Endoskeleton
Animal skeletons
Invertebrates
– Lack an endoskeleton of
bone or cartilage
– All but one animal
phylum are
invertebrates
Vertebrates
– Have an endoskeleton of
bone or cartilage
Reproduction
Sexual reproduction
egg of one individual is fertilized by the sperm of another
Hermaphroditic animals
possess both male and female sex organs
Asexual reproduction
single parent gives rise to an offspring that will be genetically
identical to the parent
Asexual reproduction of a body part!!
Fertilization /Copulation
Internal fertilization
External fertilization
Development of a fetus
Internal
External
Respiration
Depends on environment
Land
Trachea
Lungs
Diffusion through body wall
Water
Gills
Diffusion through body wall
Sponges
Sponges
Phylum Porifera
Saclike body with many pores
Mainly aquatic animals
Filter feeders
Asexual and Sexual Reproduction
– Hermaphroditic
– Usually not self-fertilizing
Spicules
– For internal support (endoskeleton)
– Asymmetrical
– Incomplete digestive tract
Cnidarians
Cnidarians: True Tissues
Phylum Cnidaria
Tubular or bell-shaped
with radial symmetry
All aquatic, mostly
marine
Cnidarians
Cnidocytes
– Stinging cells unique to
cnidarians
Two body types
– Polyps and medusan
Gastrovascular cavity
– Sac-like body plan
Cnidarians
Hydra
– Freshwater
– sac-like body plan with a single
opening
– Digestion begins in
gastrovascular cavity, completed
in cells
– Can reproduce sexually and
asexually (budding)
Flatworms
Flatworms
Phylum Platyhelminthes
Bilateral symmetry
Incomplete digestive tract
Acoelomate
Flatworms
Planarians
– Found in lakes, ponds, and streams
– Reproduce both asexually and sexually
Regeneration (asexual)
Hermaphroditic (sexual)
– Reciprocal transfer – simultaneous transfer of the sperm to the
genital orifice of the partner
Flatworms
Parasitic Flatworms
– Tapeworms
Endoparasites
Range in length from several millimeters to 20 meters
Tough integument to protect from host’s enzymes
Scolex
Roundworms
Roundworms: Phylum Nematoda
– Tube within a tube body plan
Mouth and anus
– Hydrostatic skeleton
– Nonsegmented
– Some roundworms are free-living, others are parasitic
Roundworms: Pseudocoelomates
Ascaris
– Move with whip-like motion
– Females are much longer than males and highly prolific
– Eggs enter host in uncooked vegetables, soil, or feces
Coelomates
The rest of the species that we will study are
Coelomates
– Bilateral symmetry
– Organ level of organization
– Tube-within-a-tube body plan
Molluscs
Molluscs
Second largest animal phylum
Unique characteristics of molluscs
– Three distinct parts
Visceral mass
Foot
Mantle
– Radula
Grasping organ for feeding
Molluscs
Gastropods
– Nudibranchs, conchs, and snails
Foot is flattened ventrally
Aquatic gastropods have gills
Terrestrial gastropods
–
Mantle has lung-like function
Molluscs
Cephalopods
– Squid, octopus, chambered
nautilus
Foot has evolved into tentacles
Extremely well-developed eyes
–
Built for speed!!
Complex behaviors
Ink glands
–
Secrete “ink” as defense mechanism
Molluscs
Bivalves
– Clams, oysters, scallops
Two-part shells (valves)
Filter-feeders
–
Water enters through incurrent siphon
Annelids
Annelids: Segmented Worms
Phylum Annelida
– Segmentation
– Hydrostatic skeleton
– Tube-within-a-tube
body plan
Annelids: Segmented Worms
Oligochetes (Earthworms)
– Locomotion
Contraction of longitudinal and circular muscles
Few setae per segment
– Gas exchange is across the body wall
Annelids: Segmented Worms
Oligochetes (Earthworms)
– Reproduction
Hermaphroditic
Worms lie parallel in opposite
directions
–
Clitellum produces mucus to keep sperm
moist
After separation, produces a slime tube
Moves eggs and sperm together for
fertilization
Slime tube then produces a cocoon
Annelids: Segmented Worms
Leeches
– Most live in freshwater
– Most are ectoparasites - have suckers for feeding
– Have same general body plan as other annelids
Lack setae
Each body ring has transverse grooves
Arthropods
Arthropods: Jointed Appendages
Phylum Arthropoda
– Over 1 million species have been described
30 million may exist (mostly insects)
– Appendages are for:
Walking, swimming, reproduction, eating, sensory reception
– Exoskeleton of chitin (must molt to grow)
– Well-developed nervous system
Brain and ventral nerve cord
Sense organs
Arthropods: Jointed Appendages
Crustaceans
– Barnacles, shrimps, lobsters, and
crabs (marine)
– Crayfish (freshwater)
– Known for their hard shells
–
Cephalothorax
– Usual anatomy is a pair of
compound eyes and five pairs of
appendages
Front two pairs have sensory
functions
Other three pairs are used in feeding
Arthropods: Jointed Appendages
Insects
– Three body regions
Head
– Sensory antennae, eyes
– Mouthparts are adapted to each
insect’s way of life
Thorax
– Three pairs of legs and the wings
Abdomen
– Contains most internal organs
Comparison of Crayfish and Grasshopper
Crayfish
– Gills
– Excrete liquid
nitrogenous wastes
(ammonia)
– No reception of sound
– Utilize uropods when
swimming
Grasshoppers
– Spiracles and trachae
– Grasshoppers excrete
solid wastes (uric acid)
– Tympanum for reception
of sound
– Have legs for hopping
and wings for flying
Arachnids: 6
pairs of appendages
Scorpions
– Oldest terrestrial arthropods
– Abdomen ends with a venomous stinger
Ticks and Mites
– Parasites
Transmit diseases such as Rocky Mountain spotted fever or Lyme
disease
Spiders
– Spiders have a narrow waist that separates cephalothorax from
abdomen
Chelicerae have fangs that deliver poison to prey
Silk glands for web-spinning
http://www.youtube.com/watch?v=kdVvoSP8QtY
http://www.youtube.com/watch?v=0LmyyXcE6rw
Millipedes and Centipedes
Millipedes:
Eat decaying plant matter
two pairs of short legs per body
segment
Centipedes:
terrestrial carnivores with poison
claws
Have one pair of short legs per body
segment
Echinoderms
Echinoderms
Characteristics of
Echinoderms
– Marine animals
– Endoskeleton made
of calcium-rich
plates
– Spines stick out of
their skin
– Adults exhibit radial
symmetry
Echinoderms
Sea Stars
– Found along shorelines on rocky surfaces
– Five-rayed body with mouth on underside and anus on
upper side
– Structures project through skin
Spines for protection
Skin gills
– Extensions of skin for gas exchange
Chordates
Chordates
Must exhibit these
characteristics:
– Notochord
– Dorsal tubular nerve cord
– Pharyngeal pouches
– Postanal tail
The Chordates………
Invertebrate chordates
– Tunicates and lancelets
Vertebrate chordates
– Fishes
– Amphibians
– Reptiles
– Birds
– Mammals
Nonvertebrate Chordates
Tunicates (sea squirts)
– Squirt water when their
siphons are disturbed
Live in ocean and are filter-feeders
Larva is bilaterally symmetrical
and has four chordate
characteristics
Adults are sessile, thick-walled,
sac-like organisms
– The only chordate
characteristics in the adults are
pharynx and gill slits
Vertebrates
Characteristics
– Have four chordate
characteristics at some point
in life
– Distinguishing features
Strong, jointed endoskeleton
Vertebral column composed of
vertebrae
Efficient respiration and excretion
Fishes
Fishes: First Jaws, Then Lungs
Adapted to life in water
– Sperm and eggs released into water
– Fertilization external
– Zygote develops into swimming larval
form
Fish vs Fishes???
2 chambered heart
Ectothermic
What are fish?
– Jellyfish?
– Starfish?
– Crayfish?
– Shellfish?
Fishes
Three main groups/Classes of
fishes
– Jawless fishes
– Cartilaginous fishes
– Bony fishes
http://www.youtube.com/watch?v=O2FInaOCqoo
Amphibians
Jointed appendages
Class Amphibia
– “two lives”
– Tetrapods
– Eyelids keep eyes moist
– Have ears
– Larynx for vocalization
– Small lungs present in
adults
Gas exchange also occurs across
moist skin
– Three-chambered heart
Ectothermic
Large mouths and consume
prey whole
Amphibians
Have either internal or external fertilization
Metamorphic life cycle
– Aquatic larva (gills) - water
– Terrestrial adult (lungs) - land
Class Amphibia
Order: Gymnophiona
Caecilians
Order: Caudata
Salamanders and
Newts
Order: Anura
Frogs and toads
http://www.youtube.com/watch?v=wXqK5QulbJ8
Reptiles
Amniotic egg
Class Reptilia
– Body is covered with scales
– Ectothermic
– Three chambered heart****
– Eyelids
Reptiles
Amniotes
Tetrapods that have a terrestrially adapted egg
Amniotic egg usually buried in substrate
Contains membranes that protect the embryo
In reptiles, internal fertilization
http://www.youtube.com/watch?v=q7CQInAXoqY&feature=related
Class Reptilia – 4 Orders
Order: Testudines
– Turtles and tortoises
Order: Crocodilia
– Crocodilians
Order: Rhynchocephalia
– Tuataras
http://dsc.discovery.com/videos/crocodile-feeding-frenzy-alligator-egg-hunt.html
http://www.metacafe.com/watch/198880/weird_nature/
Class Reptilia – 4 Orders
Order: Squamata
– SO: Lacertilia
Lizards
4 limbs and tail
– SO: Serpentes
Snakes
Limbless
– SO: Amphisbaenia
Amphisbaenians
Short tails
Scales in rings
Limbless
Subterranean
http://www.youtube.com/watch?v=Unzg7C1KJo0
http://www.youtube.com/watch?v=rwRdqkEcmbs
Birds
Class: Aves
Amniote egg with a hard shell
Internal fertilization, external
incubation
–
–
–
–
–
–
–
–
Forelimbs are modified as wings
Bones are laced with air cavities
A beak has replaced jaws
Large sternum for attachment of flight
muscles
Air sacs to increase the efficiency of
breathing
Endothermic
Four-chambered heart
Cloaca
Mammals
Class: Mammalia
body hair and milkproducing mammary glands
Adapted for active life on land
Limbs that allow rapid
movement
Four-chambered heart
Endothermic
High level of care for the young
Internal development (most)
Mammals
Monotremes
– Have a cloaca
– Egg-laying mammals
– Spiny anteater and
duck-billed platypus
Both found in Australia
– Both males and females
have modified sweat
glands and secrete milk
onto body surface
Mammals
Marsupials
– Begin development within
female’s body
born very immature
development is completed
within a pouch
Attach to nipples of mammary
glands within the pouch
– Virginia opposum is the
only marsupial species
north of Mexico
– Mainly found in Australia
Mammals
Placental Mammals
– Extraembryonic membranes are modified
for internal development
How primates differ
from most mammals :
Most are adapted for living in trees
Limbs are mobile, hands and feet have digits
Opposable thumbs (sometimes big toes)
Eyes in the front of the head
Large, complex brain
Generally give birth to one offspring at a time
– Extended period of juvenile dependency