AnimalsAnimals

What are they and how are What are they and how are they grouped?they grouped?

What is an Animal?What is an Animal?

Body StructureBody Structure Obtaining Food and OxygenObtaining Food and Oxygen Keeping Conditions StableKeeping Conditions Stable MovementMovement ReproductionReproduction

Structure of AnimalsStructure of Animals

Animals are composed of many cells Animals are composed of many cells ((multicellularmulticellular).).

CellCell: The basic unit of structure for : The basic unit of structure for all living things.all living things.

The cells of MOST animals are The cells of MOST animals are organized into higher levels of organized into higher levels of structure, including structure, including tissuestissues, , organs,organs, and and systemssystems..

Tissues, Organs, and Tissues, Organs, and SystemsSystems

TissueTissue: A group of similar cells that : A group of similar cells that perform a specific function. perform a specific function.

Example: Nerve cells working together to Example: Nerve cells working together to transport electrical signals through the body.transport electrical signals through the body.

OrganOrgan: A group of several different : A group of several different tissues working together.tissues working together.

Example: A frogExample: A frog’’s thigh bone is composed of bone s thigh bone is composed of bone tissue, nerve tissue, and blood.tissue, nerve tissue, and blood.

SystemSystem: Groups of structures performing : Groups of structures performing the broadest functions in an organism.the broadest functions in an organism.

Functions of AnimalsFunctions of Animals

From tiny worms to giant whales, animals From tiny worms to giant whales, animals are diverse. Despite their differences, are diverse. Despite their differences, however, however, all animals carry out the same all animals carry out the same basic functionsbasic functions. The major functions of . The major functions of animals are…animals are…

Obtain food and OxygenObtain food and Oxygen Keep internal conditions stableKeep internal conditions stable MoveMove ReproduceReproduce

Obtaining Oxygen and FoodObtaining Oxygen and Food

An animal cannot make its own food, it must An animal cannot make its own food, it must obtain it from eating other organisms obtain it from eating other organisms (heterotroph)(heterotroph)..

Food provides animals with raw materials for Food provides animals with raw materials for growth and with energy for their bodies growth and with energy for their bodies activities.activities.

All animals body cells need oxygen to release All animals body cells need oxygen to release energy from food.energy from food.

Some animals get oxygen from the air and some Some animals get oxygen from the air and some from water.from water.

Keeping Conditions StableKeeping Conditions Stable

Animals must maintain a stable environment Animals must maintain a stable environment within their bodies.within their bodies.

When balance is lost, animals do not survive When balance is lost, animals do not survive very long. For example, cells that get too hot very long. For example, cells that get too hot start to die.start to die.

Animals have adaptations that allow them to Animals have adaptations that allow them to stabilize their bodies in the environment they live stabilize their bodies in the environment they live in.in.

Homeostasis: Homeostasis: Keeping internal conditions Keeping internal conditions stable.stable.

MovementMovement

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

Most move freely their whole lives by Most move freely their whole lives by swimming, running, hopping, flying, etc.swimming, running, hopping, flying, etc.

Some, like oysters or barnacles, only Some, like oysters or barnacles, only move from place to place at the earliest move from place to place at the earliest stages of their lives.stages of their lives.

Animal movement is usually related to Animal movement is usually related to their needs of survival and reproduction.their needs of survival and reproduction.

ReproductionReproduction

Because individual animals cannot live Because individual animals cannot live forever, they must reproduce.forever, they must reproduce.

MOST animals reproduce sexually.MOST animals reproduce sexually. Sexual ReproductionSexual Reproduction: The process by : The process by

which a new organism develops from the which a new organism develops from the joining of 2 sex cells --- a male sperm cell joining of 2 sex cells --- a male sperm cell and a female egg cell.and a female egg cell.

Reproduction (cont.)Reproduction (cont.)

FertilizationFertilization: The joining of a sperm and : The joining of a sperm and egg cell.egg cell.

New individuals resulting from sexual New individuals resulting from sexual reproduction have a combination of reproduction have a combination of characteristics from characteristics from bothboth parents. parents.

Some animals can reproduce Some animals can reproduce asexuallyasexually as well as as well as sexuallysexually..

Asexual ReproductionAsexual Reproduction

Asexual reproductionAsexual reproduction: The process by : The process by which a single organism produces a new which a single organism produces a new organism identical to itself.organism identical to itself.

For example, animals called sea For example, animals called sea anemones sometimes split down the anemones sometimes split down the middle, producing two identical organisms.middle, producing two identical organisms.

Classification of AnimalsClassification of Animals

Scientists have identified more than 1.5 Scientists have identified more than 1.5 million species of animals!!!million species of animals!!!

Animals have been classified into roughly Animals have been classified into roughly 35 major groups of animals (35 phylum).35 major groups of animals (35 phylum).

Animals are classified according to Animals are classified according to how they are related to other animals. how they are related to other animals. These relationships are determined by These relationships are determined by an animalan animal’’s body structure, the way the s body structure, the way the animal develops and its DNA.animal develops and its DNA.

The 2 biggest groupings…The 2 biggest groupings…

Invertebrates: All animals Invertebrates: All animals withoutwithout backbones.backbones.

Vertebrates: All animals Vertebrates: All animals withwith backbones. backbones. We will be spending much of our time We will be spending much of our time

studying the vertebrates, but roughly studying the vertebrates, but roughly 97%97% of animals on Earth are invertebrates!!!of animals on Earth are invertebrates!!!

RecapRecap

All animalsAll animals:: Are made of cells, most are grouped into tissues, Are made of cells, most are grouped into tissues,

organs and systems.organs and systems. Are heterotrophs and need oxygen to survive.Are heterotrophs and need oxygen to survive. Are adapted to keep their internal conditions stable in Are adapted to keep their internal conditions stable in

whatever environment they live in.whatever environment they live in. Move at least sometime during their lives.Move at least sometime during their lives. Reproduce. Most sexually, some can perform Reproduce. Most sexually, some can perform

asexual as well.asexual as well. Are classified according to how closely they are Are classified according to how closely they are

related to other animalsrelated to other animals