what is an animal - norwell high school › ... › whatisananimal.pdf · classification of animals...

What is an Animal ?A living organism which feeds on organic matter, typically having specialized sense organs and nervous system and able to respond rapidly to stimuli

~ Cells: a basic unit of structure

~ Tissue: a group of cells that perform a specific function: i.e nerve tissue carries impulses from one body part to another; bone tissue is a hard tissue that gives bones strength

~ Organ: a group of specific tissues that combine to form an organ: i.e. a thigh bone is composed of bone tissue, nerve tissue and blood

~ System: groups of structures that perform the broadest functions of an animal; i.e. all the bones form the skeletal system

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Organisms are made up of many different systems

Functions of Animals

~ Obtain Food and Oxygen

~ Keep Conditions Stable

~ Movement

~ Reproduction

Obtaining Food and Oxygen~ all animals are heterotrophs

~ food provides animals with raw materials for growth and energy

~ different animals have special adaptations for eating and getting oxygen

~ adaptations - a characteristic that helps an organism survive or reproduce in its environment

Keeping Conditions Stable

~ animals must maintain stable internal conditions

~ animals have adaptations/behaviors to keep internal conditions stable; i.e. sweating, panting, finding shade, rolling in mud...

Movement~ all animals move at some point in their lives

~ most move freely throughout their lives: by either walking, swimming or hopping

~ some animals only move during the earliest phases of their lives~ movement ususally is related to meeting the basic need s of survival and reproduction

Movement~ All animals move in some way at some point their lives.

~ Animal movement is to meet the basic need of survival (food) and reproduciton

~ Some move early in their life and find a good place and stay in same place (such as barnacles)

Reproduction

~ most animals reproduce sexually by joining a female and male sex cell (egg and sperm)

~ some animals reproduce asexually which results in an organism that is a genetic replication of the parent

~ the joining of an egg cell and a sperm cell is called fertilization

Classification of Animals

~ Animals are classified by how they are related to other animals based on following:

- Body structure

- Development

- DNA

Biologists have classified animals into 35 major groups, each of which is called a phylum.

DNA is a chemical in cells that controls an organism's inherited characteristics.

Classification of Animals (continued)

vertebrates - animals with backbones

invertebrates - animals without backbones (makes up 97% of animals)