Kingdom Animalia. What characteristics define an animal? What characteristics define an animal?
23.1 Animal Characteristics Animals. 23.1 Animal Characteristics Multicellular Heterotrophic Lack...
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Transcript of 23.1 Animal Characteristics Animals. 23.1 Animal Characteristics Multicellular Heterotrophic Lack...
23.1 Animal Characteristics
Animals
23.1 Animal Characteristics
• Multicellular• Heterotrophic• Lack cell walls• Sexual Reproduction• Movement• Specialization – adaptation for a cell for a
particular functionCells tissues organs organ systems
23.1 Animal Characteristics
Body Structure
• Dorsal – top• Ventral – bottom• Anterior – head• Posterior - Tail
23.1 Animal Characteristics
23.1 Animal Characteristics
Body Symmetry
• Asymmetry – no symmetry
• Radial – arrangement of body parts around a central axis
- top & bottom, no front, back, or right & left sides
• Bilateral symmetry – 2 similar halves on either side of a central plane
23.2 Animal Diversity
23.1 Animal Characteristics 23.2 Animal Diversity
Radial Symmetry – allows for organism to take in stimuli from all sides
23.1 Animal Characteristics 23.2 Animal Diversity
Bilateral Symmetry – adaptation for movement
23.1 Animal Characteristics
Cephalization
• concentration of sensory & brain structures in the anterior region
No-cephalization
23.2 Animal Diversity
23.1 Animal Characteristics
Fertilization
• Gamete + Gamete = Zygote• Sperm membrane fuses with egg membrane
– causes an electrical shock that blocks entry by other sperm
• Sperm nucleus merges with egg nucleus
23.2 Animal Diversity
23.1 Animal Characteristics
Cleavage – cell divisions of the zygote immediately following fertilization
Rapidly increases # of cells, but cells do not grow in size• Increases surface area-to-volume ratio• Continues until they form a hollow ball of cells –
blastula• Central cavity - blastocoel
23.2 Animal Diversity
23.1 Animal Characteristics
Gastrulation – blastula collapses inward
• Blastopore – infolded region - will function as the gut • Gastrula – multilayered embryo• Deep cavity is formed – archenteron – embryonic stem cells
Ectoderm – outer germ (cell) layer• Skin, hair, etc.
Endoderm – inner germ layer• Digestive system
Mesoderm – layer between ectoderm & endoderm
• Muscular and Skeletal systems
23.2 Animal Diversity
23.1 Animal Characteristics 23.2 Animal Diversity
23.1 Animal Characteristics
Patterns of Development
• Protostomes – blastopore first develops into a mouth
• Deuterostomes – blastopore first develops into anus
23.2 Animal Diversity
23.1 Animal Characteristics
Types of Body Cavities
• Acoelomates – body cavity is absent– Flatworms
• Pseudocoelomate – mesoderm lines the fluid-filled coelom (body cavity)
• Coelomates – mesoderm lines the body cavity and surrounds and supports the gut
23.2 Animal Diversity
23.1 Animal Characteristics