Biology II
Chapter 1 Notes
Biology- The study of life and how it evolved.
(this is an ongoing process)
1.
Organization
2.
Emergent
properties
3.
Cellular
basis of life
4.
Heritable
information
5.
A
feeling for organisms
6.
The
correlation between structure and function.
7.
The
interaction of organisms with their environment
8.
Unity
in diversity
9.
Evolution
10.Scientific process: the hypothetico-deductive method
Each level has order and organization. We develop and learn from simple to complex,
each level building on another.
Subatomic
particles→elements→atoms→complex biological particles↓
↓
complex organ system←Organ
systems←organs←tissue←cells
↓
↓Organism→population→community→ecosystem→biomes→↓
biospheres ←
**species**
= similar organisms who can interbreed
and produce
fertile offspring.
Emergent property = a new characteristic that forms as a result
of
interactions between levels or components. *each level up has properties and
characteristics that the simpler level did not have.
Seven properties associated
with life:
1.
Order-
organisms are highly ordered
2.
Reproduction-
organisms reproduce to continue life
3.
Energy
utilization- the intake and transformation of
energy to do work
4.
Response
to Environment- organisms respond to stimuli from their environment (
adaptation/survival)
5.
Growth
and Development- inheritance etc.
(species specific patterns)
6.
Homeostasis-
regulation of internal environment even in the face of fluctuating external environments
7.
Evolutionary
adaptation- life evolves in response to the environment
Vitalism= life is a supernatural phenomenon, beyond physical
laws
Holism= a higher level of order cannot be explained by
looking at it’s parts (an organism is a living whole greater than the sum of
its parts. ie: a cell dismantled to its chemical ingredients is no longer a
cell)
Opposing
Thoughts Reductionism: The principle that a complex system
can be understood by studying its
components parts. (highly used in
biology)
**biology tries to balance both of these ideas to be able to better understand the individual organism its environment and interactions.
1.
All
living things are composed of cells
2.
Cells
come from other cells
3.
All
cells reproduce, grow & repair
Cell = the lowest level of structure capable of
performing all life’s
activities.
Discovery of Cells
¨
the
microscope let us see what was thought to be, but could not be proved
¨
Robert
Hooke 1665 saw the first dead
cell. (cork)
¨
Antonie
van Leeuwenhok 1600’s saw first living cell (pond water organisms, blood,
animal sperm)
¨
Matthias
Schleiden and Theodor Schwann 1889 stated, all living things are made of cells
Two major kinds of cells:
a.
prokaryotic
i.
evolved
first
ii.
lacking
membrane bound organelles
iii.
found
in Kingdom Monera (which was later split into Kingdom Archaebacteria and
Kingdom Eubacteria)
iv.
circular
DNA not separated from the rest of the cell
v.
tough
external walls
b.
eukaryotic
i.
evolved
when one prokaryote swallowed another which evolved into a needed organ
ii.
has
membrane bound organelles
iii.
consists
of ALL other Kingdoms (Kingdom Protista, Kingdom Fungi, Kingdom Plantae,
Kingdom Animalia)
iv.
DNA
enclosed in a nuclear envelope, therefore separated from the rest of the cell (
organized into chromosomes)
v.
plasma
membranes with some surrounded by an additional cell wall
¨
DNA
is made of four types of chemical building blocks called nucleotides.
¨
Nucleotides
encode for precise information in a gene ( the unit of inheritance from parent
to offspring)
¨
A
particular nucleotide sequence provides the same information to one organism as
it does to another (differences in organisms reflects differences in nucleotide
sequences)
Barbara
McClintock
=1983 Nobel Prize , her familiarity with Indian corn enabled her to identify a
type of genetic change not yet recognized in the scientific community.
There is a relationship between an organism’s structure and how it works
¨
the
biological structure gives clues about what it does and how it works
¨
knowing
a structure’s function gives insights about its construction
Organisms
interact with their environment, both organism and environment are affected by the
interaction.
Ecosystem
dynamics= two major processes
1.
Nutrient
cycling
2.
Energy
flow
DIVERSITY IS THE HALLMARK OF LIFE: WITHOUT IT LIFE WOULD BE VERY DULL!!
Biological diversity is enormous
5-30
million species
only
about 1.5 million species already identified (260,000
plants; 50,000 vertebrates;
750,000 insects)
Taxonomy = Branch of biology concerned with naming
and
Classifying organisms.
* categories ranked by a hierarchy—from least
inclusive
to
most specific
7 basic levels are: Kingdom, Phylum, Class, Order, Family,
Genus, Species
Six Kingdom Taxonomic System
(in order of evolution)
2.Kingdom Eubacteria û be grouped together in
3.Kingdom Protista
4.Kingdom Fungi
5.Kingdom Plantae
6.Kingdom Animalia
Even though the kingdoms have a variety of organisms
in them there is still a unity within their diversity
¨
universal
genetic code
¨
similar
metabolic pathways
¨
similar
cell structure
Evolution: a theory, the unifying theme in Biology
¨
life
evolves. Species change over time
¨
species
share a common ancestor
1859
Charles Darwin
¨
published
On the Origin of Species
¨
theme
“descent with modification” (evolution
+ natural selection over long time spans)
we just call it evolution
¨
based
on natural selection, inheritable traits and the potential to produce more
offspring than will survive
¨
traits
best suited to the environment leave a larger number of offspring
¨
natural
selection dies not create adaptations;
it merely increases the frequency of inherited variants that arise by chance
¨
adaptations
are the result of the editing process of natural selection. When exposed to specific environmental
pressures, certain inheritable variations favor the reproductive success of
some individuals over others
Descent with
modification accounts for both the unity and diversity of life:
¨
similarities
between two species may be a reflection of their descent from a common ancestor
¨
differences
between species may be the result of natural selection modifying the ancestral
equipment in different environmental contexts.
The best scientific skill is OBSERVATION
·
Good
scientists ask question and believe those question are answerable
·
Good
scientists are curious, observant and passionate in their quest for discovery
·
Good
scientists are creative, imaginative and intuitive
·
Good
scientists are skeptics
Scientific method = a process of steps to answer questions
·
Not
a rigid process
·
Based
on there being a reason why things happen
·
Requires
evidence to logically solve problems
Hypothesis = Educated guess of possible causes that
reflect past
experiences
**they may be eliminated but
not confirmed with
absolute certainty
Control group = the group in which all
variables are held constant
(this allows conclusions to be made about the effect
of experimental manipulation)
Variable
= the condition that is changed, only one item at a time
Experimental group = the group in
which one factor or treatment is
varied
Scientists must:
·
Build
on prior scientific knowledge
·
Try
to replicate experiments to check conclusions
·
Share
information
Biology is a multi-disciplinary science that requires knowledge of chemistry, physics and mathematics
Ethics = the big question: Just
because we can, should we??????