Transcript GENERAL BIOLOGY, Ch. 1

Principles of Biology
§ The Scope of Biology:
H subdisciplines
H spans over huge spans of time
and size
H continuous process of learning
H unifying themes
Unifying Themes in Biology
A hierarchy of organization
The cellular basis of life
Heritable information
The correlation between structure and
function
The interaction of organisms with their
environment
Evolution: the core theme
Scientific process: the hypotheticodeductive method
Life’s Hierarchical Order
of Organization
Ecosystem
Community
Population
Organism
Organ system
Organ
Tissue
Cell
Molecule
Atom
Hierarchical levels
Determine the level:
“Larger than
Life!!!”
Hierarchical levels
Determine the level:
“The
microcosmic
world”
Hierarchical levels
Determine the level:
“ Life in the big
“
Hierarchical levels
Determine the level:
“Lub Dub, Lub Dub”
Hierarchical levels
Determine the level:
“Ma and Pa, and
Auntie Rose and
Uncle Fritz.”
Hierarchical levels
Determine the level:
“I feel as frozen as an
icecube when its
winter.”
Each Level of Biological
Organization has EMERGENT
PROPERTIES
Property that emerges as a result of
interactions between components
“An organism is a living whole
greater than the sum of its parts.”
With each step upward in the hierarchy,
new properties emerge that were not
present at the simpler levels.
Emergent Properties
(characteristics of life)
Cellular
Order
Reproduction (biogenesis)
Growth and Development
Energy Utilization
Response to the Environment
Homeostasis
Evolutionary Adaptation
Cells
Basic unit of structure and function
unicellular/multicellular
Rober Hooke -- tree bark/cork
Antonie van Leeuwenhok -animalicules
Characteristics of cells
Prokaryotic, Eukaryotic cells
The Continuity of life is based
on heritable information in the
form of DNA
Nucleotides
linear sequence of 4 nucleotides
gene = unit of inheritance
copying DNA
passing info. Encoded
in DNA from parent to offspring.
All forms of life use essentially the same
genetic code.
Structure
Function
Biological structure gives
clues as to what it does/how
it works
photosynthesis
muscle contraction
The interaction of
organisms with their
environment
Biotic/abiotic
Nutrient cycling
Energy flow
Homeostasis
Regulatory mechanisms
ensure a dynamic
balance in living systems
Evolution, Unity, and Diversity
Diversity
5 million - >30 million species
1.5 million species have been
identified/named
Taxonomy
domain  kingdom  phylum  class 
order  family  genus  species
6 kingdoms: Monera, Archaea, Protista,
Plantae, Fungi, Animalia
Classification of Humans
1.
Kingdom: Animalia
2.
Phylum: Chordata
• a.
Notochord, dorsal hollow nerve cord, pharynx, and
gill slits in pharynx wall during at least part of life cycle.
3.
Class: Mammalia
• a.
Hair and mammary glands
4.
Order: Primate
• a.
Monkeys, apes, humans
5.
Family: Hominids
• a.
All species on or near evolutionary road leading to
modern humans.
6.
Genus: Homo
• a.
Bipedal and possess large brains relative to body
size
7.
Species: Homo sapiens
• a.
large brains
• b.
use symbolic language and with words can shape
concepts out of experiences. (cultural evolution)
Life’s Diversity
Classification of life’s diversity
in an attempt to better
understand.
6 Kingdoms
1. Animalia 2. Plantae
3. Protista 4. Monera
5. Fungi
6. Archaea
What kingdom and why?
What kingdom and why?
What kingdom and why?
What kingdom and why?
What kingdom and why?
What kingdom and why?
Kingdoms:
How are you more
like a microscopic
amoeba, than an
amoeba is like a
bacterium?
Unity in the diversity
of life
Universal genetic code
Similar metabolic
pathways
Similarities of cell
structure
Evolution
Unifying theme in biology
life evolves -- change over time
species that are very similar may
share a common ancestor
less closely related organisms may
have shared a more ancient common
ancestor
ALL LIFE IS CONNECTED
On the Origin of Species
Charles Darwin
Descent with modification
natural selection
individuals in a population of any species
vary in may inheritable traits
populations have the potential to prod. more
offspring than will survive or than the
environ. can support
those with traits best suited to the environ.
leave a larger number of offspring
natural selection does not create
adaptations
Evolution
explains the
unity and
diversity of life
The Scientific Method
Reasons for the scientific
method
Hypothetico-deductive method
5-step process
1. Observations
2. Questions
3. Hypotheses
• must be testable
4. Predictions
5. Tests
Inductive vs. Deductive
Reasoning
Specific observations  general
conclusion
inference from general premises 
specific consequences, which logically
follow if the premises are true
If…..then...
predicting exp. results that are expected if
the hypothesis is true.
Testing the Hypothesis
variables
independent vs. dependent
effect on test results
test group vs. control group
difference
size
positive control/negative control
repeatability of tests
reliability or results
Once a hypothesis is
tested, then what??????
 Conclusion/re-access the
original hypothesis
 Retest over and over again
 THEN......
 theory
 “ITS THE LAW!!!!!!!!”
The Scientific Method
An investigator spills dye on a
culture plate and then notices that
the bacteria live despite exposure to
sunlight. He decides to expose 2
culture plates to ultraviolet light--one
plate contains bacteria and dye; the
other plate contains only bacteria.
The bacteria on both plates die. Fill
in the right-hand portion of the
following diagram:
Scientific Method
Observations
Hypothesis
Experimentation
and/or observations
Conclusion
Interconnecting Webs
Organisms don’t exist in isolation
from the environment.
Producers, Consumers,
Decomposers
Photosynthesizers
carbon dioxide + water + sunlight
--> food
ALL organisms depend on producers
for food