Introduction
to
Biology
Question:
• What is Biology?
Answer:
• The scientific study of life.
Biology
• An overview:
1. Earth: Unity of Diversity
2. Evolution
3. Hierarchy of Organization
4. Emergent Properties
5. The Cellular Basis of Life
6. Scientific Method
1. Earth: Unity of Diversity
• Scientist believe there are between 5 million
and 30 million species on earth.
• To date: ~1.5 million species have been
identified.
~ 1.25 million animals
~ 250,000 plants
1. Earth: Unity of Diversity
• To organize all of these organisms, scientist
classify species into categories.
categories
• Taxonomy:
Taxonomy
the naming and classifying of
organisms.
1. Earth: Unity of Diversity
• Taxonomic groups are ranked into a hierarchy
from MOST to LEAST INCLUSIVE.
INCLUSIVE
1.
2.
3.
4.
5.
6.
7.
8.
Domain
Kingdom
Phylum
Class
Order
Family
example: Western Pond Turtle
Genus
------ Clemmys
Species
------ marmorata
1. Earth: Unity of Diversity
• There are 3 Domains and 6 Kingdoms of life:
1. Eubacteria (prokaryotic)
1. Eubacteria (Monera): Bacteria
2. Archaea (prokaryotic)
2. Archaebacteria
3. Eukarya (eukaryotes)
3.
4.
5.
6.
Protista: Simple multi or unicellular animals
Plantae: Plants
Fungi:
Yeast and mushrooms
Animalia: Animals (invert and vertebrate)
Question:
• What kingdom do viruses belong to?
• Answer: none
2. Evolution
• Life evolves and species change overtime.
• “A CHANGE IN THE GENES (DNA)”
• All life is connected and can be traced back
~3.5 billion years.
years
• Remember:
Evolution is the one biological theme that
ties all together.
together
2. Evolution
• Charles Darwin:
Darwin proposed Natural Selection
• “On the Origin of Species by Means of
Natural Selection”
• Natural Selection:
Environmental factors that favor the
reproductive success of some individuals
over others.
3. Hierarchy of Organization
• Biological organization:
Based on structural levels from
Least to Most Inclusive.
Inclusive
1. Atoms
2. Molecules
3. Organelles
4. Cells
5. Tissues
6. Organs
7. Organs systems → The Realm Of Ecology
3. Hierarchy of Organization
8. Organisms:
Organisms
species
9. Populations:
Populations
localized groups of organisms
belonging to the same species.
10. Community:
Community populations of species living
in the same area.
11. Ecosystem:
Ecosystem
community interactions
12. Biomes:
Biomes
large scale communities
13. Biosphere:
Biosphere
the sum of all earth’s
ecosystems.
4. Emergent Properties
• Properties that emerge from interaction between
components (attributes of life):
A. Complexity of organization.
B. Organisms reproduce.
C. Organisms grow and develop.
D. Organisms transform energy.
1. Autotrophic - self feeders (plants).
2. Heterotrophic - other feeders (animals).
E. Organisms respond to stimuli (environment).
F. Life evolves and adapts to the environment.
5. The Cellular Basis of Life
• Cells are the lowest level of structure capable of
all activities of life.
• Cell Doctrine: 1852 by Robert Hooke.
A. Cells are the basic unit of life.
life
B. Cells arise from pre-existing cells (mitosis).
C. Cells are surrounded by a membrane.
membrane
D. Cells transform energy (cellular respiration).
E. Cells have information retention and transfer in the
form of genes (DNA - pass to offspring).
offspring)
5. The Cellular Basis of Life
• Two major cell types:
1. Prokaryotic Cells:
a. no membrane bound organelles
b. no nuclear membrane
2. Eukaryotic Cells:
a. have membrane bound organelles
b. have a nuclear membrane
6. Scientific Method
• A process that scientists use to answer questions
about life and nature.
nature
1.
2.
3.
4.
5.
6.
7.
Observations and questions.
Formulate a testable hypothesis.
Search for relevant materials in the library.
Make predictions.
Conduct a controlled experiment.
Collect data.
Formulate a theory.