Animals Flashcards
Zoology
Study of animals
4 characteristics of animals
Multicellular
Eukaryotic
Heterotrophic
Motile
Embryology
Different cells have different functions
Germ layers
Most basic tissue formed in embryo
3 types of germ layer
Ectoderm
Endoderm
Mesoderm
Ectoderm
Layer that forms outer body
Ex. Skin, fur, scales, nervous system
Endoderm
Forms inside lining of digestive tract
Ex. Gut lining, respiratory lining
Mesoderm
Layer in between endo/ectoderm, forms most organ systems
Ex. Circulatory, respiratory, muscular systems
Coelom
Cavity that forms between 2 layers of mesoderm
Only organism that has asymmetry
sponges
What organisms have radial symmetry
Primitive animals
Starfish, sand dollars,
Cnidarians
Where is bilateral symmetry found in
Complex organisms
Cephalization
Sensory/nervous tissue is concentrated in anterior region
What does high cephalization allow?
For animals to process lots of information at once
Only motile stage of sponges life
Sperm
What systems do sponges lack?
Digestive, circulatory and nervous
Collar cells
Line the central cavity
Use flagella to create water currents that siphon water into central cavity
How many germ layers do sponges have?
0
Hermaphrodites
Capable of producing male and female gametes
How are sponges ecologically important?
Provide habitat for many aquatic species
Cnidaria
First animals to have germ layers and embryology
Includes jellyfish, coral, and sea anenomies
What germ layer do cnidarians lack?
Mesoderm
Lack internal organs
Nematocysts
Stinging cells that paralyze prey
What were the first animals to perform extra cellular digestion?
Cnidarians
What symmetry do cnidarians have?
Radial
Medusa
Cnidarian that has ectoderm face up
Polyp
Cnidarian that has endoderm side up
Phylum Platyhelminthes
Simplest form of worms
Contains flatworms
What were the first animals to have mesoderm, bilateral symmetry and chephilization?
Flatworms
Flukes
Parasitic flatworms that have digestive tracts
Have incomplete digestive system
Pharynx
Extends from mouth of flatworm, shreds food particles and sucks into digestive cavity
Pseudocoelomates
Animals with only 1 layer mesoderm
What can flatworm nervous system detect?
Blurry images
Sensing chemicals
Simplest organism known to be able to learn
Flatworm
Tapeworms
Specialized parasitic flatworm
Have evolved to lose digestive tract and sensory organs
Proglottids
Reproductive organs that release from worm once matured and exit through feces to be ingested
Phylum nematoda
Contains roundworms
Thread like
Are pseudocoelomates
First animals to have complete digestive system
Roundworms
Hookworm
Most common type of parasitic flatworm
Can infect host without being ingested
Guinea worm
Ingested when host drinks contaminated water
Who dedicated their like to eradicating Guinea worm?
Jimmy carter (U.S president)
Only 2nd eradicated disease following smallpox