Introduction to AnimalsIntroduction to AnimalsChapter 9 Section 1-2

What is an Animal?What is an Animal?EukaryoteHeterotrophMulticellular

◦Cells are usually arranged into tissues (muscle tissue)

◦Tissues are arranged into organs (heart)

◦Organs are arranged into systems (circulatory system)

Functions of AnimalsFunctions of Animals

1. Obtain food and oxygen2. Maintain stable internal

conditions3. Movement4. Reproduction

◦(Vocab to remember: sexual reproduction, asexual reproduction, fertilization)

Animal SymmetryAnimal SymmetrySymmetry: balanced

arrangement of partsTwo types

◦Bilateral - One line divides into halves that are mirror images (Isosceles triangle)

◦Radial – many lines of symmetry that all go through a central point (circle)

Asymmetry – no symmetry

Animals with Radial Animals with Radial SymmetrySymmetryParts arranged

around a center point

Live in waterDon’t have a

front or back end

Do not move fast

Animals with Bilateral Animals with Bilateral SymmetrySymmetryMore complex Have a front

endMove more

quicklyMost have

sense organs on front end (eyes, whiskers, nose, ears)