brief introduction to the animal kingdom...• phylum nematoda– roundworms (e.g. pinworm) tapeworm...
TRANSCRIPT
Brief Introduction to the Animal
Kingdom
• Vocabulary
– Vertebrate
– Invertebrate
– Detritivore
– Asymmetry
– Bilateral symmetry
– Radial symmetry
– Cephalization
• Key Concepts
– What are the characteristics of an animal?
– What are essential functions for animals to survive?
– Cephalization
– Coelum
– Pseudocoelum
– Acoelomates
– Blastula
– Blastophore
– Protosome
– Deuterosome
Which of these are “animals”?
• Characteristics all animals share:
– Eukaryotic
– Multicellular
– Heterotrophic– Heterotrophic
– Reproduce sexually
• Have specialized tissue that forms nerves and
muscles
• Cells do not have a cell wall
• Diversity in the Animal kingdom is so vast and the differences among the organisms are great
– Therefore, animals are divided into two major groups
• Invertebrates
Invertebrates
• Invertebrates
– Organisms without a backbone
• Vertebrates (Chordates)
– Organisms with a backbone
• 95% of all animals are invertebrates while 5% are vertebrates
Vertebrates
How do animals obtain food?
• Herbivore = eats plants
• Carnivore = eats animals
• Omnivore = eats plants and animals
• Detritivore = feed on decaying organic material• Detritivore = feed on decaying organic material
• Filter Feeders = aquatic animals that strain food from water
• Parasite = lives in or on another organism
• Scavenger = consumes carcasses of other organisms
• Respiration
– All animals take in oxygen and
give off carbon dioxide
– Respire through lungs, gills,
skin, or simple diffusion
• Circulation• Circulation
– Smaller animals depend on
diffusion
– Larger animals depend on a
circulatory system
• Excretion:– Primary waste product is ammonia
• Response:– Receptor cells = sound, light, external – Receptor cells = sound, light, external
stimuliNerve cells => nervous system
• Movement:– Most animals move
• Reproduction
– Most reproduce sexually = genetic diversity
– Many invertebrates can also reproduce asexually
to increase their numbers rapidlyto increase their numbers rapidly
Body Symmetry
• Body Symmetry– the body plan of an animal, how its
parts are arranged
• Types of Symmetry– Asymmetry - no pattern (corals, – Asymmetry - no pattern (corals,
sponges)
– Radial Symmetry - shaped like a wheel (starfish, hydra, jellyfish)
– Bilateral Symmetry - has a right and left side (humans, insects, cats, etc)
• Cephalization - an anterior concentration of
sense organs (to have a head)
– Animals with bilateral symmetry tend to exhibit
cephalization
• The more complex the animals becomes the
more pronounced their cephalizationmore pronounced their cephalization
Body Sides
• anterior - towards the head
• posterior - towards the tail
• dorsal - back side
• ventral - belly side• ventral - belly side
• Segmentation
– "advanced" animals have body segments, and
specialization of tissue (even humans are
segmented, look at the ribs and spine)segmented, look at the ribs and spine)
Segmented
Body Cavity
• Most animals have some type of body cavity
– A fluid-filled space between digestive tract and
body wall
– Allows digestive organs to grow– Allows digestive organs to grow
• Coelum (prounounced “see lum”)
– Body cavity that develops within the mesoderm
and is completely lined with tissue derives from
mesoderm
– More complex organisms have
• Pseudocoelum
– Body cavity is partially lined with
mesoderm
– Example: Pinworm
• Acoelomate• Acoelomate
– Organism lacks body cavity all
together
– Examples: Jellyfish, tapeworms
Animal Development
• Early Development
– Animals begin life as a zygote (fertilized egg)
• The cells in the zygote divide to form the
BLASTULA - a hollow ball of cells
• The blastula pinches inward to form three GERM LAYERS
– Ectoderm: Outermost layer
• Develops into the sensory organs, nerves, outer layer of “skin”
– Mesoderm: Middle layer
• Develops into the muscles, most of the circulatory system, reproductive system, and excretory organ systemreproductive system, and excretory organ system
– Endoderm: Innermost layer
• Develops into the digestive system and much of respiratory system
• Blastophore: digestive tract that only has one
opening to outside
• Protosomes: an animal whose mouth is formed
from the blastophorefrom the blastophore
– Example: most invertebrates
• Deuterosomes: an animal whose anus is formed
from the blastophore and the mouth is formed
for a second opening later in development
– Examples: Echinoderms and Chordates
Animal Kingdom Phyla
• Phylum Porifera –
sponges
• Phylum Cnidaria – sea
anemones, jellyfish,
hydra
• Phylum Platyhelminthes -Flatworms (e.g. tapeworms, planarian)
• Phylum Nematoda –roundworms (e.g. pinworm)
Tap
ew
orm
Pin
wo
rm
pinworm)
• Phylum Annelida -segmented worms (e.g. earthworms)
Pin
wo
rmE
arth
wo
rm
• Phylum Molluska – clams, squid snails
• Phylum Arthropoda- crustaceans, insects,
spiders
– This is the largest phylum in the animal kingdom
and contains the most number of species
• Phylum Echinodermata – starfish
• Phylum Chordata – all vertebrates