1. INTRODUCTION TO BIOLOGY
- Scientific Method
- Life’s Characteristics
- Taxonomy
- Scientific Tools

2. Science and Biology Science Biology- The study of life.
A process of inquiry to investigate the world around us.
Science discovers reliable knowledge about nature, due to the SCIENTIFIC METHOD.
Observation-> Question-> Hypothesis-> Controlled Experiment-> Collect and Analyze Results-> Publish-> Peer Review
Biology- The study of life.
From Latin: Bio- “Life”
-ology “The study of”

3. Life Characteristics Metabolism: Homeostasis:
The sum of all chemical activities in an organism.
Respiration, transport, excretion, nutrition, regulation.
Autotrophs (a.k.a producers) synthesize their own food (chemo- or photo- synthesis)
Heterotrophs (a.k.a consumers) depend on autotrophs for food
Homeostasis:
Maintaining a constant, stable internal environment.
Ex. Body temperature, hormones, blood pH

4. Feedback Mechanisms Used to maintain homeostasis
Positive Feedback – Reinforcement of a body process
“A makes more of B which makes more of A”
Ex. Birth contractions, lactation, blood clotting, fever
Negative Feedback – Counteraction of a body process
“When something goes too high, lower it.”
“When something goes too low, raise it.”
Ex. Body temperature, blood pH, blood Glucose levels

5. Life Characteristics, cont’d
Responsiveness/Sensitivity:
Response or reaction to both biotic (living) and abiotic (non-living) stimuli.
STIMULUS - A change in the internal or external environment causing a response.
Reproduction and Development:
Ability to replicate its own kind.
ASEXUAL (one cell divides into 2, into 4, etc.)
SEXUAL (zygote  cell division  cell specialization  growth  maturation)

6. Life Characteristics, cont’d
Evolution/ Adaptation:
Change in frequency of alleles (genes) in a population…not individuals!
Ability to change or adapt if the environment changes.
Best for sexual reproducing organisms.
6. Cells
The simplest unit of organization of all life.
The CELL THEORY states that all living things are made of and came from living cells, and that every cell itself is a living thing.

7. Life Characteristics, cont’d
7. Genetic Material
Living things pass on heritable information through DNA.
DNA is a double helix, consisting of two long chains of nucleotides (sugar, phosphate, base)
8. Organization (Complexity):
Hierarchical organization
Most Simple  Most Complex
Levels can vary depending on the organism

8. Organization Of Organisms
Atom- Basic unit of matter
Molecule- Atoms bonded together
Organelle- Functional units of cells
Cell – Basic unit of living organisms
Tissue- Group of cells performing a similar function
Organ- Group of tissues performing a similar function
Organ system- Group of organs performing…..
Organism- Any living thing (Can also be a single cell)
Species – Organisms that can interbreed and produce fertile offspring.
10. Population– All members of the same species in an area.
11. Community – Groups of different populations in an area.
12. Ecosystem– Community with the non-living environment.
13. Biosphere – Anyplace life exists on Earth.

9. Classification of Organisms
TAXONOMY
The branch of biology that deals with the naming of
organisms.
Binomial nomenclature system (started by Carolus
Linnaeus in 1753).
Genus species
Species
Genus – closely related species.
Family
Order
Class
Phylum
Kingdom (Bacteria, Archaebacteria, Protists, Fungi, Plants, Animals)
Domain (Eubacteria, Archaea, Eukarya)

10. PROKARYOTIC EUKARYOTIC
no nuclear membrane
DNA enclosed in nuclear membrane
DNA in a circular strand
structurally simple
structurally complex
metabolically complex
many organelles including mitochondria (most) and chloroplasts (when photosynthetic)
cell fusion does not occur
cell fusion does occur
small size: µm
larger cell size µm

12. Phylogeny & Terminology
PHYLOGENY (Phylogenetic Tree) – Evolutionary history of
a group.
ROOT – The base…the lower down, the more ancient
BRANCH – Shows species (or populations) through time.
NODES (Forks):
Ancestral group splits into two (or more) descendent groups.
If there is more than 2 ancestral groups, then it shows POLYTOMY.
OUTGROUP – A group known to have diverged (split off) before the rest of the groups under consideration.
TIP (Terminal Node): Species alive at present day or have gone extinct.
SISTER TAXA: Taxa occupying adjacent tips.

13. SISTER
TAXA
TIP
POLYTOMY
OUTGROUP
NODE
BRANCH
ROOT

14. MONOPHYLETIC GROUP: PARAPHYLETIC GROUP:
Ancestral species and all descendants on one branch.
Kingdoms Fungi, Plantae, and Animalia.
PARAPHYLETIC GROUP:
One branch that does not include all the descendants of
a common ancestor.
- MUCH more diversity exhibited
Kingdom Protista.

15. Monophyletic
Group
Paraphyletic
Group
SISTER
TAXA
TIP
POLYTOMY
OUTGROUP
NODE
BRANCH
ROOT

16. Scientific Tools- Microscopes
Light Microscopes
Compound Microscope (transmitted light)
Dissecting Microscope (reflected/transmitted light)
Electron Microscope
Shoots electrons through the specimen
Downside? Kills specimen on contact- Cannot view
movement and behavior
Benefit? Gives extremely detailed images