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Published byJonas Chapman Modified over 9 years ago
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What is an Animal?
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Characteristics of Animals All animals have several characteristics in common. What are the four common characteristics of animals? – Eukaryotic – Multicellular – Heterotrophic – No cell wall
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What Do Animals Do to Survive? Feeding Respiration Circulation Excretion Response Movement Reproduction
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Trends in Animal Evolution Your survey of the animal kingdom will begin with simple forms and move through more complicated ones.
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Phylogenetic relationships: Trends in Animal Evolution
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Cell Specialization and Levels of Organization Groups of specialized cells that work together form tissues. Tissues join together to form organs. Group of organs work together to form organ systems – EX: Circulatory system
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Cephalization Concentration of sense organs and nerve cells at the front end or head of the body.
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Animal Body Plans What is symmetry? Arrangement of body parts on opposite sides of a plane or line Asymmetry Radial Symmetry Bilateral Symmetry
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Animal Body Plans Acoelom – Without a body cavity
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Animal Body Plans Pseudocoelom – Fluid-filled internal space that is in direct contact with the wall of the digestive tract.
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Animal Body Plans Coelom – Fluid-filled body cavity completely lined by a layer of mesoderm cells and suspending internal organs
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Animal Body Plans
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How do these body plans develop?
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Early Development
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Development of Animal Body Plans Cell Division – The zygote divides by mitosis and cell division to form two cells in a process called cleavage. – How important is this first cell division? Problems can led to defects in embryo Zygote
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Development of Animals: Gastrulation (a process of forming cell layers) The zygote undergoes a series of divisions to form a blastula, which is a hollow ball of cells. DemoPhylums Porifera and Cnidaria only have two layers
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Protostome vs. deuterostome Mouth is formed from the blastoporeAnus is formed from the blastopore
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Formation of a Coelom (body cavity): Neurulation Body cavity – a fluid-filled space that lies between the digestive tract and the body wall. Gastrula Embryo Development
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