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What is an Animal?. A multicellular organism of the kingdom Animalia that uses locomotion , metabolism , pronounced response to stimuli , and fixed bodily structure. Characteristics of Animals.
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What is an Animal? A multicellular organism of the kingdom Animaliathat uses locomotion, metabolism, pronounced response to stimuli, and fixed bodily structure
Characteristics of Animals • All animals have several characteristics in common. What are the four common characteristics of animals? • Eukaryotic • Multicellular • Heterotrophic • No cell wall
What Do Animals Do to Survive? • Feed • Respire • Circulate • Excrete • Respond • Move • Reproduce
Trends in Animal Evolution • Your survey of the animal kingdom will begin with simple forms and move through more complicated ones.
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
Cephalization • Concentration of sense organs and nerve cells at the front end or head of the body.
Flatworm • Range in size from .2 inches to 50 feet!
Animal Body Plans • What is symmetry? Arrangement of body parts on opposite sides of a plane or line Asymmetry Bilateral Symmetry Radial Symmetry
What type of symmetry? • Radial
What type of symmetry? • Bilateral
What type of symmetry? • Asymmetrical
What type of symmetry? • Radial
Animal Body Plans • Acoelom • Without a body cavity
Animal Body Plans • Pseudocoelom • Fluid-filled internal space that is in direct contact with the wall of the digestive tract.
Animal Body Plans • Coelom • Fluid-filled body cavity completely lined by a layer of mesoderm cells and suspending internal organs
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 lead to defects in embryo Zygote
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. Demo PhylumsPorifera and Cnidaria only have two layers
Protostome vs. deuterostome Mouth is formed from the blastopore Anus is formed from the blastopore
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