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The “BIOLOGY I SURVIVAL GUIDE”
Total magnification of a microscope is calculated by multiplication = ocular x objective.
If the ocular is10x and the low power objective is 20x, then the total magnification is 200x.
When using a balance scale, calibrate the scale so it reads zero BEFORE ANYTHING is placed upon it.
OR subtract the weight of the container on the scale that is used to hold something by knowing its empty weight.
If measuring the volume of something in a liquid, subtract the starting volume from the ending volume.
When using a thermometer allow time for the temperature to stabilize. The freezing point of water was chosen to be zero
degrees Celsius (0 oC), while the boiling point of water was selected to be 100 degrees C.
ANYTHING that can be tested and measured is a potentially valid question for research or experimentation.
(Science is unable to answer questions that can’t be measured or tested.)
The Scientific Method is a process used to learn and/or test things. While there are various “scientific methods” used, they
all operate around some basic steps similar to this outline…
1. Observation – gathering information. This includes learning by see, feel, smell, hear, & taste tasting.
Observations can also include reading text or taking measurements.
2. Question – asking about an unknown (including anything that can be tested).
3. Hypothesis – A small statement (“an educated guess”) that can be tested.
The hypothesis should…identify the independent (tested) and dependent (measured) variables
A. be written in an “If…,then…” format,
B. the “If…” portion of the statement should outline the experimental treatment/test, &
C. the “then…” portion of the hypothesis should predict the outcome by stating what you think will result/happen
in response to the treatment (and address the question at hand).
4. Experiment – the procedure used to test a hypothesis. Trying something to see what happens.
5. Results – This is what happened (usually past tense) in the experiment. Collected data.
6. Conclusion – This is what the results/data means (usually present tense). Supported finding.
7. Theory – a belief that becomes accepted as true because it has been supported by many findings.
Pie Chart – used when data… (picture on the right)
1. has specific categories
2. is reported PERCENTAGES and the sum of all the
categories adds up to 100%
Key = independent variable (tested)
Percent/number = dependent variable (measured)
On scatter plots, line graphs, and bar graphs the…
X axis (bottom) = independent variable (tested)
Y axis (side) = dependent variable (measured)
Scatter Plot – (pictured on the right)
A scatterplot is used to report two sets of quantitative (numerical)
data sets, each point being reported on a case by case basis.
Line Graph –
Bar Graph –
Maintaining an Objective (fair) & Accurate Experiment – (Control, Independent Variable, Dependent Variables,
Sample Size, and quantitative vs. qualitative data measures)
The goal of science is to learn new things, so it is good to be objective and seek the truth by ensuring that an experiment is
done correctly with good controls, is repeatable, and tested a sufficient number of times (not just once or twice).
Only one thing at a time should change between the different groups being tested. The one thing that is changed is known
as the independent variable, which is purpose for the experiment. Independent refers to being “in charge” or influencing.
Experimental controls (constraints) keep everything fair between the various treatment groups by keeping all non-tested
factors the same. Every experiment should have a control group to establish a base line. A placebo is a type of control
group (a fake treatment) that goes through all the other conditions to determine if any other factors may have influenced the
outcome/measurements besides the item(s) being tested.
The dependent variables are what is measured, and record the what is responding or being influenced by the treatments.
Sample size (n) is another factor that influences the credibility of an experiment. The more something is tested and found
to be consistent, generally the more accurate the test is.
When possible, small sample sizes, qualitative measures, non-repeatable experiments, biased experiments, &
inconsistent controls are all faults and should be avoided when pursuing science.
A null-hypothesis is another explanation for the same outcome.
CHEMISTRY
1. Atoms – the smallest form of an element that still maintains the properties of that element.
2. Atoms are also the basic structural components of all matter.
3. Sub-atomic particles are the small parts that are than an atom. Remember,
“sub” means beneath or less than so these are less than an atom.
4. The nucleus of an atom contains protons and neutrons.
5. Atomic # = the # of protons
6. Atomic Mass = P + N (the electrons are so small they are not included).
7. Atomic Charge = P – e (Protons are +, Neutrons are neutral, & electrons
are -).
8. An atom is composed of a nucleus and the outer electron fields. These
fields can hold less electrons than they want, but not more. The first
electron field around an atom’s nucleus wants 2e-. The second & third efields want 8e- To get their desired number, atoms will bond w/ other
atoms that will give, take, or share electrons.
The nucleus also contains the neutrons, which do NOT have a charge.
9. A chemical element is a pure chemical substance consisting of one type of atom.
10. When two or more atoms bond together, they form a molecule. Molecules can be formed by atoms of the same element
or from different elements. When the elements are different, the molecule is referred to as a compound.
Covalent bonds form when two atoms share electrons. NOTE: start off w/ no charge, but end up w/ polar sides
Ionic bond form when atoms exchange electrons. This occurs when ions of opposite charges are attracted to one another.
NOTE: start off w/ a charge, and end up neutral.
Water (H2O). Water is a polar molecule, which means one (H) side is positive & the other (O) side is negative. The polar
positive side of one water molecule (positive of one) & polar negative of another water molecule (the negative of another)
create hydrogen bonds.
Water’s polarity gives it unique characteristics…
1. Hydrogen bonds give water cohesion properties (ability to stick to itself) &
surface tension (bugs on pond),
2. Water’s ability to stick to other things is known as adhesion,
3. Water molecules line up when frozen, causing ice to expand…making ice
less dense.
Water is also a temperature stabilizer because it has a “high specific heat,” which
means it resists temperature change.
pH – measures the acidity/base (amount of free hydrogen) of a solution.
0 (strong acid)
(weak acid)
7
(weak base)
(strong base)
ACIDIC [H ]
NEUTRAL
BASIC [OH ]
The LOWER the pH value, the GREATER the concentration of H+ ions in a solution.
The HIGHER the pH value, the GREATER the concentration of OH- ions in the solution.
+
Synthesis enzyme (ex. Found in ribosomes)
-
Decomposition enzyme – (ex. Found in lysosomes)
A catalyst speeds up a reaction but is not altered by
the reaction. Enzymes are organic catalysts. Some
enzymes put substrates together, while other
enzymes take substrates apart. Temperature and pH
influence enzyme activity.
ATP/ADP cycle
The adenosine triphosphate (ATP) breaks into adenosine diphosphate (ADP)
+ Phosphate.
ATP stores energy. This energy becomes available for cellular activities
(metabolism) by breaking a phosphate (P) molecule from ATP.
ADP is a byproduct of the ATP cycle, and is recycled for later use.
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Photosynthesis means to make from light (sugar is stored chemical energy)
6CO2 (6 carbon dioxide) + 6H2O (6 water) + energy (sunlight)  6O2 (6 oxygen) + C6H12O6 (1 sugar)
Cellular Respiration is the breakdown (“burning”) of fuel (glucose) by a cell, which requires oxygen (O2).
6O2 (6 oxygen) + C6H12O6 (1 sugar)  6CO2 (6 carbon dioxide) + 6H2O (6 water) + energy
Aerobic Respiration is the metabolism of carbohydrates in the presence of oxygen (“Air robic” – with air/breathing)
1 GLUCOSE typically makes 36 ATP molecules (2 in the cytoplasm, and 34 in the mitochondria)
Anaerobic Respiration is the metabolism WITHOUT oxygen (NOTE: the “AN” in Anaerobic means without air).
BIOMES – environment types NOTE THE TYPES OF ADAPTATIONS NEEDED by LIVING THINGS
Temperate grasslands - moderate rain, changing temperature & seasons, good soil, grasses. RISKS ARE WINDS & FIRE.
Tropical rainforests - lots of rain, high temperatures. Diverse life. Many decomposers. Nutrients are taken up quickly by
the many life forms, leaving the soil low in nutrients. Broad leaves to collect sunlight.
Deciduous forests - Moderate rain, changing temperature, trees lose leaves in winter, animals hibernate during the winter.
Coniferous (taiga) forest – cold & little rainfall. Trees have needles year
round. Animals have hair, big feet for snow.
Savanna - Hot, seasonal rainfall. (Africa)
Deserts - Very dry, little plant life, hot. Organisms need ways to save
water (scales on reptiles and wax on plants).
Tundra – Cold, frozen ground. Very little/no plant life. Animals are
typically white & have a lot of body fat to keep warm.
Abiotic factors – non-living factors: air, water, minerals, temperature, etc.
Biotic factors – living factors in an environment, come from organisms.
Ecology – The study of organisms and their environment.
Food chain/web – a model that represents the feeding relationships within
an environment. It shows how food, matter, energy, etc cycle within an
ecosystem resulting from organisms consuming each other.
Energy - Only 10% of the energy from each level of the energy is passed
onto the higher levels of the pyramid. The other 90% is lost into the
environment as heat.
Troph (as in the Trophic Levels) – “Trophic level” refer to each step
of the energy pyramid. The largest level in the energy pyramid is the
first level, which is the producing level. The second level is the “first
order CONSUMER (eater), which include herbivores (plant eaters),
omnivores (organisms that eat both plants and animals), and
carnivores (meat eaters). Scavengers are opportunistic feeder that
eats whatever it can find, and decomposers include bacteria and fungi
that break down organic matter. The energy pyramid is similar to the
bio-mass pyramid and the pyramid of numbers (populations).
Autotroph/producers – makes its own energy, including
plants…which are the basis of energy production in the energy
pyramid. This is the largest level of the energy pyramid.
Heterotroph/consumers – Energy from something else, meaning consumes something (eats) to get energy. First level
consumers are on the 2nd level of the energy pyramid, second level consumers are on the 3 rd level of the energy pyramid,
etc. Heterotrophs include herbivores, omnivores, carnivores, insectivores, scavengers, & decomposers.
Systems and Interactions – How different groups or systems interact or influence each other. If all the mosquitoes in the
world died, then fish and other organisms would have lost a food source and some other organisms may die as a result.
Predator/Prey relationship – The predator follows the prey in BOTH physical location and in population size. When the
prey population goes up, the predator population will soon go up. This will drive the prey population down, which will
then drive the predator population down. As a result, the prey will go back up, and the predator will follow.
Three types of Symbiosis (living together)
1. Mutualism – both benefit
2. Commensalism – one benefits & the other not affected.
3. Parasitism – one benefits at the expense of the other.
Carbon cycle
Know the photosynthesis and cellular respiration equations. Know the main form of carbon include carbon dioxide (CO2),
carbohydrates (CH2O), & fossil fuels. Carbon enters the atmosphere during cellular respiration & burning of fossil fuels.
Nitrogen cycle
-Nitrogen fixation in the ground (ammonia) occurs from lightening or by bacteria in the soil or in plant roots.
-Nitrogen can go back into the air by denitrification or by the burning of fossil fuels.
-Ammonia in the ground breaks down into nitrites and nitrates.
-Nitrogen is needed to make amino acids, amine groups, and proteins.
Primary succession is the first time an ecosystem develops (an examples may islands from volcanoes or a new lake).
Secondary succession is the recovery of an ecosystem after some type of major interruption/disaster (fire, pollution, etc).
A population grows in 4 major stages. These stages include…
1. Initial growth (getting started)
2. Exponential growth (rapid)
3. Leveling-Off growth (slowing down)
4. Carrying Capacity (maximum # sustainable)
A climax community is fully developed community with many species.
The difference between a climax community and a carrying capacity (of
population growth) is the carrying capacity only considers one species,
while the climax community includes all the species in an area. (Learn
how to relate the concept of predator/prey relationship to this graph).
Greenhouse effect is a process of heating up the earth by trapping sunlight and heat within our atmosphere.
ALL CELLS CONTAIN a cell membrane, cytoplasm, & ribosomes.
The cell theory states…
1. Cells come from pre-existing cells,
2. Cells are the basic unit of life, &
3. All living things are made of cells
Prokaryotes do not contain organelles. No nucleus, chromosomes are in the cytoplasm. The first cells on earth.
Eukaryotes – Cells contain organelles (membrane bound structures in the cell), include protists, fungi, plants, & animals.
Cilia- many short hair like structures on a cell that can be used to move the cell or move a fluid across the surface.
Flagella – a single long hair like structure that is used to move a cell (swim) like a sperm.
Cells walls – Provide structural support for the cells and regulate what goes into and out of the cell. NOT IN ANIMALS.
Cell membrane – regulates what goes in and out of the cell. Found in both plants and animals.
Passive transport – transportation of something through a cell membrane without energy from a [high] to a [low].
Diffusion – going from a high concentration to a low concentration.
Osmosis – the diffusion of water from a [high] to a [low].
Hypotonic – less mixture makes cells swell.
Hypertonic – more mixture makes cells shrink.
Isotonic – equal mixture, cells stay the same size.
Active transport – transporting through channels from a [low] to a
[high].“active” since it requires energy while it makes things more
concentrated.
Cell structures and roles
Nucleus – (organelle) the control center of the cell. Regulates the
cellular activities, contains (DNA) in chromosomes.
Vacuole – A storage compartment to store water, nutrients, &
waste until needed or removed. Vacuoles are large in plants.
Chloroplast – In plants. Produces energy from sunlight by
combining water & carbon dioxide to make carbohydrates.
Ribosome – Helps make proteins by containing enzymes.
Cytoplasm – A semi-granular fluid inside the cell.
Mitochondria – An organelle that acts like the power-plant for the
cell makes energy available for the cell by making ATP.
Golgi apparatus – An organelle that makes and transports proteins
Endoplasmic reticulum – An organelle that makes and transports proteins
Lysosome – An organelle that contains enzymes for breaking down waste. Not found in most plants.
Reproduction – Organisms need to produce offspring (babies) to replace individuals within a population as they die off.
Without reproduction, a population (and life) would die off.
Asexual reproduction occurs in organisms that do not need a mate to reproduce. This occurs primarily in bacteria, archae,
and protists. (There are a few plants & a few animals that can reproduce asexually, but such isn’t typical).
Mitosis cell division for growth & development – This type of cell division produces 2 identical somatic cells that are
diploid (2n). (n represents the number of chromosomes found in the .
1.
2.
3.
4.
5.
Interphase – stage between cell divisions. Interphase includes three stages…
A. G1 - growth one, in which the cell gets larger),
B. S - synthesis, in which the DNA is duplicated. “)” becomes “)(“, &
C. G2 - growth two, in which extra organelles are produced to prepare for mitosis & cell division).
Prophase - DNA condenses into chromosomes and nucleus disappears,
Metaphase - chromosomes line up,
Anaphase - chromosomes split, &
Telophase - cell membrane splits and divides, creating two new identical diploid (2n) “daughter cells” for growth.
Sexual reproduction requires opposite
sexes and reproduce by making gametes
(sex cells: sperm/egg) via meiosis.
Meiosis – reductional division for
reproduction requires meiosis to produce
haploid cells known as gametes…
including the sperm/eggs.
1.
Interphase – see description
above (in mitosis).
The first division of meiosis is known as
“meiosis I,” and separates the homologous
chromosomal pairs.
2. Prophase I – “tetrids”
(homologous chromosomes) pair
up. Crossing over occurs for
independent assortment
3. Metaphase I – homologous chromosomes line up
4. Anaphase I – homologous chromosomes separate (gene segregation)
5. Telophase I – diploid cell divides creating haploid cells
Then we proceed directly into the 2nd stage of meiosis… “meiosis II”
6. Prophase II –
7. Metaphase II – chromosomes line up
8. Anaphase II – chromosomes separate into chromatids
9. Telophase II – cell divides creating sperm or eggs. These four new haploid (1n) gametes have genetic variation.
Fertilization - Two haploid cells, sperm & egg, combine to form a zygote, with a diploid set of DNA in its chromosomes.
Genes make up the chromosomes and code for everything in our body. They do this by using Nucleotides, which are the base
pairs found on the “rungs” of the DNA double helix model. The nucleotides found in DNA include Adenine (A), Guanosine
(G), Thymine (T), & Cytosine (C), and can be seen below. A purine group pairs with a pyrimidine group. When DNA copies
itself during replication, “A” pairs with “T” (A-T) while “C” pairs w/ “G” (C-G). If a DNA sequence was CTA-GTC, then
the pairing DNA sequence would be GAT-CAG.
Transcription is the process of making
messenger RNA (mRNA) from a DNA strand.
During this process, all the base pairs work the
same as they do during DNA replication except
RNA does not contain thymine (T), as thymine is
replaced with Uricil (U) on a RNA strand. If a
DNA sequence was GAT-CAG, then the
complimentary mRNA sequence would be CUAGUC. (Note: the DNA portion still contains T,
only the mRNA does not contain T).
Amino Acids contain an “amino
group,” and are essential in
building proteins, such as
muscle or hormones.
The mRNA is read by ribosomes
three nucleotides at a time and
are known as codons. Each
codon codes for a particular
amino acid. As the codon is read
by the ribosome the tRNA
(which has the complimentary
anti- codon) brings the amino
acid corresponding to the codon.
Joining these amino acids
together produces a Polypeptide
chain, which folds into itself to
form a protein.
Replication
DNA   DNA
Transcription
DNA   mRNA
Translation
mRNA   tRNA   Protein
Gregor Mendel is often considered the founder of modern genetic theory by studying genetics in the green pea plant.
Genetics – The study of heredity. This is the study of how characteristics are passed from parent to offspring.
Heredity – passing of characteristics from parent to offspring through genes.
Trait – A characteristic that is inherited, being passed from parent to offspring.
Allele – The alternative forms of a trait or gene.
Genotype – The genetic code an organism has for a trait or traits.
Phenotype – The way an organism looks showing which allele(s) is/are expressed.
Homozygous – When both alleles for a given trait are the same.
Heterozygous – When both alleles for a given trait are different.
Dominant – The allele that will be expressed in a heterozygous individual.
Recessive – The allele that is NOT expressed in a heterozygous individual.
Recessive alleles are only expressed in homozygous recessive genotypes.
Gene – A specific nucleotide sequence that controls the expression of a trait.
Genome – The entire genetic code of an organism, includes all genes (traits).
Loci – The location of a given set of genes on the genome. The genes address.
DNA chain – an alpha helical structure containing the genetic code… meaning the DNA chain looks like a ladder twisted
like a screw. The genes/alleles for our traits are paired/lined up in this chain. DNA - deoxyribonucleic acid.
Haploid – contain only half of the chromosomes (one set of chromotids) for an organism. This is the end result of meiosis
for the production of sperm and eggs (gametes).
Diploid – contains twice as much DNA as a normal cell. Having two complete sets of homologous chromosomes.
Chromosomes – DNA molecules that transport/carry the genetic information from generation to generation or cell to cell.
Mutations (mistakes) occasionally occur and form alternate forms (genes, alleles, traits), leading to adaptation or death.
Hardy-Weinberg Equalibrium equation: p + q = 1 and also p 2 + 2pq + q2 = 1
Filial – generation of offspring. F1 (1st generation of offspring/babies…the “children”),
F2 (2nd generation of offspring, these are like “grandchildren”)
Simple problems – monohybrid cross (only concerned with one trait, AA x aa). Be sure you can determine the alleles,
gametes, genotypes, and phenotypes. Also try Punnett’s squares with AA x Aa, Aa x aa, Aa x Aa, etc.
Blood types – an example of a simple genetic problem that you need to know…
Type A (IAIA or IAi) – parents were both type A or one type A and one type O
Type B (IBIB or IBi) – parents were both type B or one type B and one type O
Type AB (IAIB) – one parent was type A and the other was type B
Type O (ii) – both parents were type O
Karyotypes – A karyotype is a pictured representation (diagram) of
the chromosomes. Each chromosome will be paired with another
that looks just like it except for the last chromosome which is called
the sex chromosome since it is different in males than in females. A
human has 23 pairs of chromosomes (a human diploid cell would
have 46 chromosomes). For a human, n = 23, 2n = 46.
Autosomal traits – Traits that are controlled by genes found on the
autosomes (the non-sex chromosomes). The inheritance is no
different in males than it is in females.
Sex Linked Traits – Sex-linked traits are controlled by genes
found on the X chromosome. Females are XX, males are XY.
Females only need one dominant gene to express a dominant gene,
but they need two copies of a recessive X-linked trait to show that
trait. Males only need 1 copy of an X-linked gene to express it
since the Y sex chromosome is blank.
Pedigrees – Males will be distinguished as squares while females
are designated with circles. The pedigree will show the inheritance
of a trait usually by darkening or not darkening in a circle or
square black. Use the information provided in a pedigree to
identify the types of mode of inheritance in a population. Notice if
the males and females express the trait equally. If males & females
display the trait in the same manner, then the trait is NOT sex
linked, and therefore is on the autosomal chromosomes. If males &
females can display the trait differently, then it is sex-linked.
Create Punnet squares if needed.
Gel Electrophoresis is a lab procedure
That can be used to identify certain strands of DNA, RNA, & proteins. It works by isolating particular strands with some
type of marker. The DNA, RNA, and proteins separate on the basis of their molecular weight. This process can be used to
find genes…and can also be used in DNA tests to confirm parentage (confirming who the parents are).
Aristotle developed a primitive classification system (300 B.C.). His flawed system impacted biology by emphasizing a
need to classify organisms by their similarities. The problem with his system was it was too simple...only separating
organisms into either “plants” or “animals” & then dividing each category by their method of travel (water, land, or air).
Linnaeus developed our modern system of classifying in the 1700’s, after the microscope was invented by looking more
carefully at cell structures and characteristics. We have improved upon his system to develop our current system of
Taxonomy – DKPCOFGs (3 domains, 6 kingdoms and classification of organisms)
-Domain, Kingdom, Phylum, Class, Order, Family, Genus, species. All levels of taxonomy are capitalized except the
species. Know the levels of taxonomy in order, and also know which group has the most organisms (larger groups).
Additionally, the scientific names are Latin, and are written in italic letters. Ex. Homo sapiens.
-Binomial nomenclature is a naming system invented by Linnaeus. All organisms can be identified by two specific
names (Genus & species). This allows scientists to identify and classify common organisms on the basis of their
characteristics and traits with other similar organisms (which may be helpful in medicine). Latin is used so scientists
accurately communicate information without the need of a translator.
3 Domains & 6 (A-F) Kingdoms –
1. The Archaea (archaebacteria)- Archaea are prokaryotic cells. The cell walls of Archaea contain no peptidoglycan.
2. The Bacteria (eubacteria)- Bacteria are prokaryotic cells. The cell walls of Bacteria contain peptidoglycan.
3. The Eukarya (eukaryotes)- cells with organelles. Eukarya are subdivided into the following kingdoms:
C. Protista Kingdom - Protista are simple, most are unicellular (a few are multi-cellular) eukaryotic organisms that have
cell walls. Examples include slime molds, euglenoids, algae, and protozoans. Protists can move. They are the 1st eukaryotes
(cells that organelles). Some are autotrophic (make their own food/energy) while others are heterotrophic (obtain food from
other sources).
D. Fungi Kingdom - Fungi are unicellular or multi-cellular organisms with eukaryotic cell types. Fungi have cell walls but
are not organized into tissues. They do not carry out photosynthesis, instead they obtain nutrients through absorption. As a
result, fungi are heterotrophic (obtain food from outside source, decomposers). Examples include mushrooms, yeasts, and
molds. Often found in moist, dark areas.
E. Plantae Kingdom - multi-cellular organisms composed of eukaryotic cells (containing organelles). They have cell
walls, contain chloroplasts, and are organized into tissues. They obtain nutrients by photosynthesis and absorption. Roots
obtain water and other nutrients. Plants require sunlight, carbon dioxide, & water. Plants produce carbohydrates (C6H12O6).
F. Animalia Kingdom - multi-cellular eukaryotic (cells have organelles) organisms. Animals do not have cell walls.
Animals require oxygen to burn carbohydrates as fuel. Some animals are symmetrical (radial symmetry, bilaterally
symmetrical), some are asymmetrical.
-Some animals do not have a skeletons, but some have an exoskeletons (skeletons on the outside of the body like a
lobster), and others have endoskeletons (skeletons on the inside of the body like in humans).
-Segmented body parts include the head, thorax (chest region), abdomen (belly region), & appendages (arms & legs).
Vertibrae animals (animals with a backbone) include fish (ectothermic cold blooded), amphibians (ectothermic), reptiles
(cold blooded ectothermic), birds (“endothermic” warm blooded), & mammals (endothermic, live birth, & have
mammary glands for milk production).
Redi did an experiment to test for spontaneous generation to see if
meat could produce flies. He found spontaneous generation to be
false…and proved it to be impossible. He found that the maggots
had to get to the meat from flies.
Needham boiled a “soup” to kill micro-organisms, & noticed that within a few days
life would grow in the soup. Needham didn’t heat it up enough to kill everything, so
life came back and he mistakenly thought life could spontaneously generate.
Spallanzani showed that micro-organisms moved through the air, & these microorganisms could be killed by heat.
Pasteur also found similar results by using a flask with a “soup” in it. He heated up the soup in the flask to kill all life in
the flask. Then, he sealed the flask, and then let it sit for a while to see if things would grow in the soup. What they found
was life only grew if things in the air were allowed to get into the flask. If the bacteria in the air was kept out of the flask,
then the soup did not contain life.
Fossil record – relative dating methods identify “old” organisms
by how deep they are buried, with the older stuff deeper and the
younger stuff closer to the top. Unfortunately, not all organisms
produce fossils.
An organism is LIKELY
to fossilize IF it is
1. Hard bodied
2. Is buried quickly
3. Existed in large numbers
An organism is NOT likely
to fossilize if it is…
1. Soft bodied
2. Is not buried
3. Existed in small numbers (rare)
Adaptation – Organisms respond (adapt) to changes (stimuli) in
the environment; which can include physical changes, behavioral
changes, or both; however, in adaptation the species is still the
same species.
Evolution – The changing of species over time to such a degree
that they become a “new kind,” (a new species). The proposed
methods for both adaptation and evolution are believed to occur
by Darwin’s proposed theory and steps of natural selection.
Natural selection is a process by which nature operates to ensure
the “survival of the fittest.” This theory states it is the organisms
that are the most fit for an environment are the ones that live and
therefore the ones that produce the next generation of offspring.
Evolution theory suggests that the new species results from
accumulating adaptations that naturally occur over time and only if these adaptations can be passed by on to the offspring
through genetics. While observations of adaptations have been made and that adaptation is clearly a factual event within
any given species, it is just theory that the evolution can actually create a new species.
Malthus - Learned the human population would exceed resources and cause overpopulation and competition. His work
influenced Darwin by leading to the 3rd step (competition) of resources.
Lamarck – Believed organisms could gain traits by their experiences. He knew populations of organisms would develop
the traits they needed to survive, but he had the mechanics of how this happened WRONG. He thought experiences
influenced inheritance, and didn’t realize that competition is what was actually culling out (killing or preventing the
reproduction of) the individuals that didn’t have the necessary traits.
Lyell – Studied geography. He noticed that the continents moved…and this provided Darwin and other evolutionists with a
means of explaining how populations could separate (become isolated) from one another so they could develop isolated
mutations. This provides a means for divergent evolution and adaptive radiation.
Darwin/Wallace – (mid 1800’s) developed the steps of Natural Selection, which led to the theory of “evolution by natural
selection.” Darwin wrote a book on this called “Origins of the Species.” Darwin studied birds and other animal life in the
Galapagos Islands. Darwin measured fitness by the ability to reproduce. Natural Selection – (see the next objective below)
Natural selection – Selection by nature. The process of natural selection results from the following 4 steps…
1. Over-production (having a lot more than will survive) of offspring (babies)
2. Variations exists within the population (not all babies are the same)
3. Some variations do better than others leading to competition (the strong survive).
4. The survivors breed and make the next generation of offspring, which look more like the strong survivors.
Artificial selection – Selection by man, where man controls which organisms breed create influence future populations,
examples would include any domesticated species.
Organisms have variation within a population (resistance to pesticides, herbicides, antibiotics, camouflage, etc), and via
competition…those who have the ability to survive reproduce…producing stronger populations in the future.
Homeostasis – maintaining the same internal environment. This theme of biology is related to organization system, be it a
body system, cellular system, or an ecosytem. Homeostasis is necessary for life…without it chaos (disorder) occurs and
life dies and falls apart. This is why an organism is called an ORGANISM. Organs, organ systems, ecosystems, etc
MUST have order. When homeostasis is lost, all life is lost. Relates to “organization” in the characteristics of life.
Characteristics of life…Organization, Adaptation, Growth & Development, Reproduction, Metabolism, Cells, DNA
Chemical Evolution – The development of the chemicals
and matter (the ingredients) necessary for life, such as
nucleic acids, amino acids, Carbon, Hydrogen, Oxygen
based molecules, etc.
Organic Evolution – The “evolution” of living matter to
higher/more complex forms.
Endosymbiotic theory – (pictured on the right)
The joining of prokaryotes with mitochondrial like and
chloroplast like “organelles”…creating the eukaryotes from
the prokaryotes…which created cells with organelles (more
complex life forms). This belief developed by noting that
mitochondria and chloroplasts both have their own
DNA…independent of eukaryotic nuclear DNA.
Divergent evolution,
Adaptive radiation
Homologous structures
Vestigial structures
Analogous structures & Convergent evolution
Stabilizing selection
Directional selection
Disruptive selection
Micro-evolution
Punctuated Equilibrium