Introduction to Living
Things
1.2, 1.3, 1.4
Organism
• Any
living thing
⚫Bacteria
⚫Animals
⚫Fungi
⚫Plants
⚫Etc
Characteristics of L.T.
• In
order to be considered alive, organisms
must have these 5 characteristics:
⚫Living things are organized
⚫Living things respond to stimuli
⚫Living things use energy
⚫Living Things grow and develop
⚫Living things reproduce
Living things are organized
• Every
living thing is made up of one or more cells.
⚫Cells=the basic unit of life
⚫Cells contain the hereditary material, called DNA
Living things respond to stimuli
•
Stimulus=something that causes a change in an organism
•
Response= the reaction to the stimulus
•
Homeostasis= an organisms ability to keep proper
conditions inside, no matter what is going on outside
Living things use energy
•
Plants, and some bacteria get energy from the sun
•
Animals get energy from food
Living things grow and develop
•
Growth=organism gets bigger
•
Development=Changes that take place during the lifetime
•
Lifespan= How long an organism is expected to live
Living things reproduce
• Reproduction=making
babies
Living things have 2 needs
1.
A place to live (habitat)
1. Must be a place that suits the needs of the
organism
What else?
2. Raw materials
• ALL
organisms need water to survive
• Humans
also need
⚫Food
⚫Oxygen
• Plants
also need
⚫Sunlight
⚫Carbon dioxide (plants do not need oxygen!)
Where does life come from?
• Living
things only come from other living things
⚫This is called biogenesis
How are living things classified?
Carolus Linneaus
• Born
Carl Linne in 1707
• Looked
for a way to classify organisms
⚫Based his classification on how organisms looked
⚫Example: All trees together, all bear-looking creatures together, all
fish together, etc.
• Developed
Binomial Nomenclature
⚫2 word naming system still used today.
Binomial Nomenclature
•2
word naming system developed by Linnaeus
⚫1st word=genus
⚫A group of closely related organisms
⚫Ex. Pinus = pine trees
⚫2nd word=species
⚫Tells us something about the organism
⚫Ex. Pinus virginana
Rules for Scientific Names
1.
First word capitalized
2.
Second word lowercase
3.
Both words in italics or, if handwritten, underlined
Example:
Homo sapiens or Homo sapiens
What is wrong with these Scientific
Names?
• canus
• Felis
familiaris
Domesticus
• Equus
caballus
Why use scientific names?
•
4 main reasons
1.
To avoid mistakes/confusion
2.
To show how organisms are related
3.
Because they give us information about the organism
4.
Allows organisms to be easily organized
1. To avoid confusion/mistakes
•
So we can avoid confusion/mistakes
⚫We use some words to refer to many organisms that are
actually not closely related
⚫ Black Bear & Koala Bear⚫ Koalas are NOT bears
2. To show how organisms are related
•
The first word gives us the genus, which is a related group of organisms
⚫Canus lupis=wolf
⚫Canus familaris=dog
⚫Canus latrans=coyote
3. The names give us some
information about the organism
•
It may be who discovered the species, where it is found, or a feature
•
Nothura darwinii
Cornus florida
Allow organisms to be easily
organized
•
Organisms part of the same genus are grouped together
⚫Phylogeny=grouping organisms based on relationships
Modern Classification
•
Life is broken down into categories
•
3 Domains
⚫Bacteria
⚫Archaea
⚫Eukarya
Kingdom
•
Life is broken down into categories
•
6 Kingdoms
⚫Domain Bacteria
⚫ Kingdom-Eubacteria
⚫Domain Archaea
⚫ Kingdom-Archaea
⚫Eukarya
⚫ Animalia
⚫ Plantae
⚫ Fungi
⚫ Protista
Eubacteria
•
“True” Bacteria
•
Single cell
Archaea
•
Similar to bacteria
•
Single cell
Animalia
•
Animal kingdom
•
Many cells
Plantae
•
Plant kingdom
•
Many cells
Fungi
•
Mushrooms, mold, yeast
•
Many cells
Protists
•
Mostly one cell
•
Most are microscopic
More classification levels
•
Phylum
•
Class
•
Order
•
Family
•
Genus
•
Species
Species
•A group of organisms that can reproduce and
have fertile offspring
Mnemonic for remembering levels of
organization
•
Did
•
Domain
•
King
•
Kingdom
•
Phillip
•
Phylum
•
Come
•
Class
•
Over
•
Order
•
For
•
Family
•
Great
•
Genus
•
Spaghetti
•
Species
Tools for Identifying Organisms
•
Field Guide & Dichotomous Key
•
Field Guide-Pictures and descriptions of organisms
Tools for Identifying Organisms
•
Dichotomous Key
⚫Detained list of characteristics that helps identify organism