Transcript Introduction to Animals Notes

Introduction to Animals
INTRODUCTION TO ANIMALS
• Most diverse
kingdom in
appearance
• More than 1
million species!
• Each phylum has
its own typical
body plan
(arrangement)
WHAT IS AN ANIMAL?
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Animals:
are heterotrophic
are eukaryotic
are multicellular
lack cell walls
WHAT IS AN ANIMAL?
• 95% = invertebrates (do not have backbone)
• 5% = vertebrates (have a backbone)
WHAT IS AN ANIMAL?
• Anatomy = the structure of the
organism/organs
what it is
• Physiology = study of the functions of
organs
how it works
WHAT IS AN ANIMAL?
• Homeostasis (balance) is maintained by
internal feedback mechanisms
• Ex: dog panting releases heat, you sweat
to release heat
FUNCTIONS OF ANIMALS
• Feeding  animals must obtain energy by eating
• Examples of types of feeding:
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Herbivore = eats plants
Carnivore = eats animals
Omnivore = eats plants and animals
Scavenger = eats dead organisms
Detritivore = feed on decaying organic material
Filter Feeders = aquatic animals that strain food from
water
– Parasite = lives in or on another organism (symbiotic
relationship)
FUNCTIONS OF ANIMALS
• Respiration animals require oxygen
• Take in O2 and give off CO2
• Lungs, gills, through skin, simple diffusion
FUNCTIONS OF ANIMALS
• Circulation  animals must move
necessary materials within their bodies
• Very small animals rely on diffusion
• Larger animals have circulatory system
FUNCTIONS OF ANIMALS
• Excretion  animals must expel waste
• Primary waste product is ammonia
Liquid waste
FUNCTIONS OF ANIMALS
• Response  animals respond to a
stimulus
• Receptor cells = sound, light, external
stimuli
• Nerve cells = nervous system
FUNCTIONS OF ANIMALS
• Movement 
• Most animals are motile (can move)
• Muscles usually work with a skeleton
FUNCTIONS OF ANIMALS
• Reproduction  animals must reproduce
• Most reproduce sexually = genetic diversity
• Many invertebrates can also reproduce
asexually = to increase their numbers rapidly
LEVELS OF ORGANIZATION
• Cell Specialization and Levels of Organization:
cells  tissues  organs  organ systems
EARLY DEVELOPMENT
• Zygote = fertilized egg
• Blastula = a hollow ball of cells
• Blastopore = the blastula folds
in creating this opening
• Protostome = mouth is formed
from blastopore
• Deuterostome = anus is
formed from blastopore
• Anus = opening for solid waste
removal from digestive tract
EARLY DEVELOPMENT
• The cells of most animal
embryos differentiate into
three layers called germ
layers:
• Endoderm = (innermost)
develops into the lining of
the digestive tract and
respiratory tract
• Mesoderm = (middle)
muscle, circulatory,
reproductive, and excretory
systems
• Ectoderm = (outermost)
sense organs, nerves, outer
layer of skin
BODY SYMMETRY
• Body Symmetry - the body plan of an
animal, how its parts are arranged
• Asymmetry - no pattern (corals, sponges)
BODY SYMMETRY
• Body Symmetry - the body plan of an
animal, how its parts are arranged
• Radial Symmetry - shaped like a wheel
(starfish, hydra, jellyfish)
BODY SYMMETRY
• Body Symmetry - the body plan of an
animal, how its parts are arranged
• Bilateral Symmetry - has a right and left
side (humans, insects, cats, etc)
CEPHALIZATION
• Cephalization - an anterior concentration
of sense organs (to have a head)
• The more complex the animals becomes
the more pronounced their cephalization
BODY PLAN
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anterior - toward the head
posterior - toward the tail
dorsal - back side
ventral - belly side
SEGMENTATION
• Segmentation - "advanced" animals have
body segments and specialization of
tissue (even humans are segmented, look
at the ribs and spine)
BODY CAVITY
• Body Cavity Formation: A fluid-filled space
where internal organs can be suspended
TYPES OF ANIMALS
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Phylum Porifera
Typically asymmetrical
Lack tissues and organs
Adults are sessile
Mostly marine
Sexual and asexual reproduction
Example: sponges
About 10,000 species
TYPES OF ANIMALS
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Phylum Cnidaria
Radially symmetrical
Have distinct tissues
Marine and freshwater
Examples: jellyfish, hydra, coral
About 10,000 species
TYPES OF ANIMALS
• Phylum Ctenophora
• Radially symmetrical
• Transparent, gelatinous marine animals
resembling jellyfishes
• Propelled by cilia
• Examples: comb jellies
• About 100 species
TYPES OF ANIMALS
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Phylum Platyhelminthes
Bilaterally symmetrical
Acoelomates
Body flat and ribbon-like
Lack true segments
Organs present
Examples: Planaria, Tapeworm,
Schistosoma
• More than 18,000 species
TYPES OF ANIMALS
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Phylum Nematoda
Roundworms
Body slender and elongated
Pseudocoelomates
Oneway gut
Examples: Ascaris, pinworms, hookworms,
Trichinella, and Wuchereria
• More than 80,000 species
TYPES OF ANIMALS
• Phylum Rotifera
• Small, transparent,
wormlike or spherical
animals
• Bilaterally symmetrical
• Pseudocoelomates
• Almost all live in fresh
water
• Example: rotifers
• About 1,750 species
TYPES OF ANIMALS
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Phylum Annelida
Bilaterally symmetrical
Serially segmented worms
Protostomes
Examples: earthworms, leeches
About 15,000 species
TYPES OF ANIMALS
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Phylum Mollusca
Soft-bodied animals
Coelomates
Protostomes
most have a radula
Terrestrial, freshwater, and marine
Examples: clams, octopuses, snails
More than 110,000 species
TYPES OF ANIMALS
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Phylum Arthropoda
Bilaterally symmetrical
Coelomates
Protostomes
Segmented bodies
Paired , jointed appendages
Chitinous exoskeleton
Aerial, terrestrial, and aquatic forms
Examples: insects, spiders, crustaceans
About 1 million species
TYPES OF ANIMALS
• Phylum Echinodermata
• Adults are radially symmetrical
– five-part body plan
• Coleomates
• Deuterostomes
• Most forms have a water
vascular system with tube feet
for locomotion
• Marine
• Examples: sea star, sand dollar,
sea urchin
• About 7,000 species
TYPES OF ANIMALS
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Phylum Chordata
Bilaterally symmetrical
Deuterostomes
Coelomates
Have 
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A notochord (early backbone and spinal cord)
A dorsal nerve cord
Pharyngeal slits
A tail at some stage of life
• Aquatic and terrestrial
• Examples: fishes, amphibians, reptiles, birds, mammals
• More than 47,000 species
Phylum Chordata
FISHES
REPTILES
AMPHIBIANS
BIRDS
MAMMALS