Biology Introduction
Scientific Method
Steps of the Scientific Method
1. Observation
2. Hypothesis
3. Experimental Design/Data Collection (Testing the
Hypothesis)
4. Analysis (Explaining the Data)
Important Scientific Method Terms
-Control  Factor in an experiment that stays the same throughout the
course of the experiment. All good experiments have at least one control
-Variable  Factor in the experiment that changes. The fewer the
variables in an experiment, the better the design.
-Theory  Hypothesis that is tested repeatedly and never disproved
Scientific Law/Principle  Scientific truths that are valid everywhere in
the universe
Fact  Truth known by actual experience or evidence
Belief  Opinion or conviction that something is true
Themes of Biology
Biology- Study of Life
Branches of Biology
Botany- Plants
Anatomy-Structure
Cell Biology- Cells
Physiology- Processes
Zoology-Animals
Genetics- Inheritance
Evolution- Change in organisms over time
Biochemistry- Chemistry of processes in organisms
Ecology- Organisms & Environment
Microbiology- Microscopic Organisms
Organism – Anything capable of carrying out life processes
Major Themes in Biology
1. Cell Structure & Function
Unicellular Organisms  1 cell
Multicellular Organisms  More than 1 cell
2. Internal Stability ability to maintain internal conditions
3. Reproduction & Inheritance
Sexual reproduction between 2 individuals
Asexual reproduction  1 cell splits to form 2 cells
4. Evolution- species change over time
5. Interdependence of organisms (ecology)  Relationship
between organisms & environment
6. Matter, Energy, & Organization Harvesting energy for life
Autotrophic Use energy directly from sun for food
Heterotroph  must take in food for energy
Unicellular or multicellular?
Autotroph or Heterotroph?
Autotroph or Heterotroph?
Autotroph or Heterotroph?
Properties Of Life
1. Made of cells
2. Reproduction
3. Universal genetic code
4. Growth and development
Growth- Increase in Amount of material in an organism
Development- Series of changes an organism undergoes in
becoming an adult
5. Obtain & use energy (from food or sun)
6. Respond to their environment
Stimulus: anything in an organism’s environment that
causes it to react
7. Homeostasis: Organisms maintain constant internal
conditions regardless of external changes
Examples?
8. Evolve: Species change over time
Taxonomy and Classification
Taxonomy- Science of identifying,
classifying, and naming organisms
Taxa- Categories into which biologists
classify organisms
Why Do We Need to Classify
Organisms?
Common names like frog and worm don’t
tell us enough information
Common names are misleading
Common names vary from country to
country
Early Classification System
Designed by Aristotle
Divided into 2 groups- Plants
and Animals
Modern Classification System
•Binomial nomenclature (2 names)
•Developed by Carolus Linneaus in 18th
century
•Organisms organized by structural
features
Taxa
•Kingdom, Phylum, Class, Order, Family,
Genus, Species
•King Phillip Came Over For Good Soup
Scientific Names
•Organism referred to by genus and species
•Genus capitalized, species is not
•Entire name is either underlined or italicized
Classification
Kingdoms of Life
• Traditionally, 5 kingdom system used to
classify life…
1.Protista
2. Fungi
3. Plantae
4. Animalia
5. Monera- which includes
Archae (Kingdom: Archaebacteria)
Bacteria (Kingdom: Eubacteria)
Domains
As biologists recognize the differences between
the 2 kinds of prokaryotes, they also saw
similarities among all eukaryotes.
So, a new system that was proposed that divides
organisms into 3 Domains based on cell
type, genetics, and nutrition
1. Bacteria
2. Archae (Ancient unicellular organisms similar to
bacteria)
3. Eukarya (Plants, animals, and fungi)
Monera
Unicellular vs.
Multicellular
Unicellular
Prokaryote vs.
Eukaryote
Prokaryotic
Nutrition
Heterotrophic or Autotrophic
Reproduction
Asexual
Movement
None
Environment
Aquatic or Terrestrial
Other Info
Some help in fighting disease
Examples
Bacteria
Protista
Unicellular vs.
Multicellular
Unicellular
Prokaryote vs.
Eukaryote
Eukaryotic
Nutrition
Reproduction
Heterotrophic or
Autotrophic
Asexual or Sexual
Movement
Cilia or Flagella
Environment
Aquatic or Terrestrial
Other Info
Some eat bacteria
Examples
Amoeba, Algae, Diatoms, &
Paramecium
Fungi
Unicellular vs.
Multicellular
Unicellular OR Multicellular
Prokaryote vs.
Eukaryote
Eukaryotic
Nutrition
Heterotrophic
Reproduction
Asexual or Sexual
Movement
None
Environment
Terrestrial
Other Info
Decomposers
Examples
Mold, yeast, & mushrooms
Plantae
Unicellular vs.
Multicellular
Multicellular
Prokaryote vs.
Eukaryote
Eukaryotic
Nutrition
Autotrophic
Reproduction
Asexual or Sexual
Movement
None
Environment
Aquatic or Terrestrial
Other Info
Insects aid in pollination
Examples
Mosses, Ferns, Shrubs, Trees, & Flowering
Plants
Animalia
Unicellular vs.
Multicellular
Multicellular
Prokaryote vs.
Eukaryote
Eukaryotic
Nutrition
Heterotrophic
What is the most diverse group
of animals?
Arthropods!!
•Most diverse phyla
•> 1 million species have been
described.
•2 out of every 3 organisms
known on Earth are arthropods
Reproduction
Asexual or Sexual
Movement
Yes (at some stage)
Environment
Aquatic or Terrestrial
Other Info
Largest kingdom  over 1,000,000
species!
Examples
Sponges, Jellyfish, Worms, Insects, Fish,
Mammals, & Birds