1. Section 1- What is an Animal?
Chapter 1
Section 1- What is an Animal?

2. Structure of Animals
Cell – Basic unit of structure and function in living things
Group of cells – tissue – organ
Groups of structures that perform the broadest functions of an animal are systems.

3. Functions of Animals
The major functions of animals are to obtain food and oxygen, keep internal conditions stable, move, and reproduce.

4. Obtaining Food and Oxygen
Obtains food by eating other organisms
Food provides animals with raw materials for growth
To release energy from food, the body’s cells need oxygen.

5. Keeping Conditions Stable
Animals must maintain a stable environment within their bodies.
If the balance is lost, the animal cannot survive for long.
Cells that get too hot start to die = dogs panting

6. Swimming, walking, hopping
Movement
Swimming, walking, hopping
Movement is related to meeting the basic needs of survival and reproduction.

7. Reproduction
Sexual reproduction – develops from the joining of 2 sex cells (fertilization)
Asexual reproduction – process by which a single organism produces a new organism identical to itself.

8. Classification Of Animals
35 major groups each of which is called a phylum
Animals are classified according to how they are related to other animals. These relationships are determined by an animal’s body structure, the way the animal develops, and its DNA

9. Invertebrates – Without a backbone Vertebrates – Have a backbone
Classification
Invertebrates – Without a backbone
Vertebrates – Have a backbone
97 percent are invertebrates

10. Section 2
Animal Symmetry

11. Bilateral – 1 line that divides it into halves that are mirror images
Animal Symmetry
Bilateral – 1 line that divides it into halves that are mirror images
Radial – many lines that all go through a central point

12. Symmetry and Daily Life
Depending on their symmetry, animals share some general characteristics.
Animals with symmetry – complex
Animals without symmetry – simple body plans

13. Animals With Radial Symmetry
The external body parts of animals with radial symmetry are equally spaced around a central point, like spokes on a bicycle.
Examples: sea stars, jellyfishes, sea urchins
All live in water
Don’t move fast = move along with the current

14. Animals With Bilateral Symmetry
More complex, larger, move quickly
Have a front and back
Most animals have bilateral symmetry
Have sense organs in their front ends that pick up information about what is in front of them
Examples: nose, eyes, whiskers