INTRODUCTION TO ANIMALS

Chapter 27 Sections 1 & 2Chapter 37 Section 1

General Features of Animals

Over 1 million different kinds of animal species

Common features Heterotrophy Mobility Multicellularity Diploidy Sexual Reproduction

Heterotrophy

Animals are heterotrophs They can not make their own food

Most animals move from place to place looking for food

Once food is located it is eaten and digested by the body

Mobility

Animals can perform rapid, complex movements

They move by muscle cells that contract

MULTICELLARITY DIPLOIDY

Animals have multiple cells

Examples: Skin cells, hair cells, muscle cells, kidney cells

Adult animals have two copies of each chromosome

One set from the father and one from the mother

Sexual Reproduction

Almost all animals reproduce sexually by producing gametes (sex cells)

Female eggs are much larger than male sperm

Body Symmetry

Refers to an animals body shape Asymmetrical – irregular in shape Radial symmetry – have body parts arranged

around a central axis Bilateral symmetry – body design in which

there are distinct right and left halves

Body Functions

Digestion Food is broken down

Respiration Animals breathe (lungs, gills)

Circulation Blood is moved throughout the body

Nerve Impulses Messages are carried throughout the body

Support Framework for the animal

Excretion Waste removal

Reproduction

Sexual New individual is formed from the union of

male and female sex cells Asexual

Does not involve the fusion of sex cells

Levels of Cellular Organization

Organism Organ System Organ

Tissue

Cell

Cells

Many different kinds of cells in the body Skin, muscle, hair, cardiac (heart), etc

Stem Cells Cells that have the potential to develop into

any type of cell Research is being done to use stem cells to

repair damaged tissue

Tissues

A group of similar cells that work together to perform a specific function.

Epithelial Lines the body

Nervous Carries information throughout body

Connective Supports, protects, insulates body

Muscle Responsible for movement

Organ Systems

Two or more types of tissues working together to perform a specific function

Circulatory – transports nutrients, wastes, etc Digestive – breaks down food Endocrine – regulates body Excretory – removes wastes Immune – fights disease Integumentary – (skin) – protects body Muscular - movement Nervous – controls and regulates body Reproductive – produces offspring Respiratory – moves air Skeletal – protects and supports body

Body Cavities

Cranial – holds the brain Thoracic – upper chest (lungs, heart,

protected by rib cage) Spinal – down center of back, holds spinal

cord and nerves Abdominal – digestive organs (stomach,

gall bladder, liver, pancreas)

Body Cavities

Endothermy

Humans are endotherms, like all mammals.

Humans maintain a constant body temperature of 37ºC (98.6ºF)

The human body uses a great deal of energy to maintain a constant body temperature.