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June 2015, Final Review sheet

Tamar

p
...

Diffusion – the movement of a particle or molecule from high concentration to low
(Concentration – how many molecules per given volume), or the movement of
molecules down the concentration gradient (high to low)
...

When you put a lot of molecules (food coloring) into a volume (water) they first come
in together and have many collisions
...
Now there are less collisions
...
The purpose of Diffusion is to get
Equilibrium
...

Example: there is a lot of oxygen molecules outside the cell (high
concentration) but a little in the cell
...
The same thing happens when the cell has a high concentration of Carbon
dioxide while the outside has a low concentration of carbon dioxide
...
Simple Diffusion – small/ non-polar molecules (like the oxygen and carbon dioxide)
that diffuse in or out of a cell directly through the phospholipid bilayer
...
Facilitated Diffusion (with helper) – large polar molecules require a helper (the
proteins embedded in the bilayer)
Factors that affect Diffusions Rates
1
...
Concentration – the higher concentration the more the molecules collide !
diffusion occurs faster
3
...
11
...
So only the very few free water
molecules can go through
...
The solute
(sugar) concentration is the same because it is proportional which means it
reached equilibrium
...
We put a semi permeable membrane (Dialysis Tubing) with 1%
starch and 15% glucose
...

Osmosis in Animal Cells
The cell has sugar, proteins, lipids, and more as there solute (ex: 10%)
...
The solute on the outside of the cell
is equal to the solute on the inside of the cell
...
The water moves in and out of the cell
...


-

Hypotonic – a solution that has less solute than the cell (hypo = Low) – only animals
cells
...
You can die from having hypotonic cells
...
+ Lysis

-

Hypertonic – the cell has less solute than the solution
...
You can die from having hypertonic cells
...


Osmosis in Plants Cells
Water is stored in the central vacuole of the plant cell
...
The water
goes in making it a Hypotonic Solution
...
Turgid (normal) – a swollen plant cell where all
the organelles and nutrients can circulate
...


-

If plants were living in a hypertonic solution, then the plant cell will take out its water
and it will Shrivel and die
...
The cell wall with stay up and strong because it
is made up of Cellulose
...


So, animal cells must be in an isotonic solution and the plants cells must be in a hypotonic
solution
...
In plants, the central vacuoles and cell wall allow plants to maintain optimal
osmotic pressure (tries to get to a Hypotonic solution/ Turgid)
...
Single Celled Organisms – don’t have cell walls,
vacuoles or kidneys
...

Active Transport – requires energy, against concentration gradient (moves from low to high
concentration) – opposite of passive transport
Sodium-Potassium pump – found in cell membrane of some cells (nerve cells), made
up of proteins
...


o

Every pump moves 3 Na out of the cell at a time
...
The pump takes 3 Na from the inside of the cell
2
...

o

Causes a shape change of the Na/K pump binding site in order for the Na/K
to pop out of the binding site outside the cell
...
3 Na pop out of pump ! outside
4
...
ATP is removed
6
...

1
...

Ex: Pancreatic cells – insulin leaves the cell by Exocytosis
...
Endocytosis – molecules enter the cell
a
...
Usually solid gets “eaten”
...
Amoeba using his pseudopods (fake feet) to engulf food (molecules)
ii
...
Pinocytosis – cell drinking – liquid around the cell enters into pocket in the
membrane by gulping it
...
Non-specific
...
Receptor Mediated Endocytosis – specific binding site on the surface of a
cell – specific for molecules
...
The pocket breaks off into the cell and forms a vesicle
...

i
...
Cell has
LDL receptors that bind LDL with the cholesterol
...

1
...


Energy
Sun – the source of all energy
Law of Conservation of energy – energy cannot be created nor destroyed (solar energy goes
to plants, converted in photosynthesis, produces glucose, we eat the glucose and use the
energy)
-

Energy can be converted from one form to another

-

Energy – the ability to do work (Chemical, potential
...
! = chemical change (product)

-

Potential Energy – stored energy, everything on earth has potential energy (potential
to fall …)
...


-

Kinetic Energy – energy of motion ! Brownian motion of our molecules

-

How does energy get into your body through glucose? Plants use solar energy for
photosynthesis and the energy is stored in the covalent bonds in the glucose (potential
energy)
...
Then the burnt energy becomes ATP by
Cellular Respiration
...
(Think of it like the bank = storage, and the
ATP Is the cash put into the candy machine
...


-

After an ATP is used (phosphate breaks via hydrolysis and releases energy) then it can
recharge ! ADP ! AMP – once a phosphate breaks off
...


-

Why do you need so much energy in your body? 1000’s of chemical reactions taking
place all the time
...

o

in order to have a chemical reaction:
1
...
collide together ! so strongly that a bond is formed (kinetic energy)
3
...

Enzymes – proteins that speed up chemical reactions (Catalyst = speed up) – specific
structure and shape (1, 2, 3 & 4 structures)
...

o

Active Site – opening in the enzyme that is a very specific shape so that the
substrate (reactants) will bind
...


o

The reactants must be in the same shape as the binding site – how the
reactants align

o

The enzymes-substrate complex squeezes the reactants so that they will be
able to form a bond – collide
▪
▪

o

Lock and key model – the substrates fit into the enzyme like a key in a
lock – proved wrong
Induced Fit model – Clasping hands – “shaking hands”
...


Then it yields and has a different shape

Factors that affect the Rate of Enzymatic Reactions
1
...
Temperature ! higher temperature = molecules move faster
o

Every enzyme has an Optimal Temperature (ideal) – temperature of enzymes
depending on the organism
▪

Human enzymes: 37 degrees Celsius

▪

Bacteria – hot springs: 100 degrees Celsius

▪

Fish – colder

o

When the body temperature goes beyond the optimal temperature ! enzyme
denatures (unravels) ! shape of the enzyme unravels and the shape of the
active site is lost ! temperature must go way beyond
...


3
...
4, stomach: 2, small intestine: 8
...
Again it depends on where the
enzymes are
...

Coenzymes – extra helper, molecule that must bind the enzyme in addition to the
substrates for the chemical reaction to occur
...
Some enzymes are inactive until the
coenzyme binds
...

-

Series of chemical reactions
...
C6H12O6+ 6O2 ! 6CO2 + 6H2O +
ATP (glucose + oxygen ! Carbon dioxide + water + energy)

Cellular respiration – harvest/ extract the energy from glucose and converts it to ATP in
the Mitochondria (pic in one note of mitochondria)
...
Slow process to
strip energy from glucose
...
Glycolysis – in the cytoplasm (not in the mitochondria)
...

o

Glycolysis = Sugar splitting
...
It goes from a 6 carbon sugar molecule (C-C-C-C-C-C), goes through
intermediate steps (middle steps- product formed in the middle of the
pathway) P-GAL, and becomes a two 3-carbon chains with a phosphate, and
then the phosphate leaves and you are left with the two 3-carbon chains (two
piruvates)
...
When the ATP is attached to the
glucose with the enzyme, Kinase, leaves you with the glucose with a phosphate
attached and an ADP
...


o

In the pathway some of energy is used to make ATP, and the rest goes to the
NAD+

o

NAD+
▪

Coenzyme (vitamin)

▪

Binds active site with substrate

▪

High energy electron carriers – stores the extra energy

▪

Takes two H from Glucose ! NADH with two electrons
...


▪

NAD+ + 2H (2 electrons) ! NADH (now has no energy)
•

Enzyme used: Dehydrogenase – takes energy out of Glucose (H) –
remove a Hydrogen

▪

In the pathway, you start with two NAD+ and end up with two NADH
...


In order for Cellular respiration to happen you need Oxidation – Reduction (LEO GER)
-

Loose Electrons is called Oxidation and Gain Electrons is called Reduction
...


o

The glucose id being oxidized (loses electron)
...

1
...
One carbon gets
stripped of all its energy and is needed to leave/ get released
...
And the energy gets
stored in the NADH
...

They need to be brought into the Krebs cycle using the coenzyme A called CoA
(vitamin B)
...

2
...
It binds and becomes 6C’s
forming the first product Citric Acid
...
You can’t break all the bonds at
once because it is so unstable that it can explode
...
After, there is a
rearrangement of atoms ! bonds are formed + broken ! the rest of the energy is
extracted + stored in NADH and also FAD+ ! FADH2
...


3
...
Made up of molecules and proteins embedded in the inner membrane
...
The NAD+ goes back to
Glycolysis + Krebs
...


o

There are series of REDOX (reduction – GER, oxidation – LEO) reactions in the
ETC
...
There are molecules in the proteins where the electrons go

through
...
Then there is a chain of oxidation and
reduction through the rest of the proteins
...

The final electron acceptor is the Oxygen and he gets reduced
...

o

Each of the molecules take a bit of energy as the electrons move through the
ETC and at the end the energy doesn’t have any more energy
...
The H+ go from the matrix
through the inner membrane through active transport (low ! high) to the
inter-membrane space
...


o

All energy from the NADH (energy storage) is in the H+ in the inter-membrane
space
...
There is only one protein that can bring the H+ back to
the matrix which is called ATP synthase – enzyme which is part of the ETC
(only opening for H+ to reenter the matrix)
...


o

Every 2 electrons that come from NADH has enough energy to make 3 ATPs
...
Depending if the cell is using more NADH or
FADH the number of ATPs made will change
...
36
– 38% energy glucose has been extracted
...
6 degrees)
...
If it doesn’t work, then you can’t make ATP which kills you
...
– Due to the ADP + P ! ATP (substrates/ kinase)
...


o

Oxidative Phosphorylation – the 32 ATP’s you make in ETC
...

a
...
Instead of the
inner mitochondrial membrane their ETC is in the cell membrane
...
4
...
But, 4 billion years ago there were
prokaryotes – bacteria which could make 2ATP without oxygen
...


Fermentation – breaking down Carbs in the absence of Oxygen
...
It wouldn’t use ETC because you don’t
have oxygen so the fermentation lets you rely on glycolysis
...
Without ETC, because of lack of oxygen, NADH is not converted to
NAD+ - we run out of NAD+ - glycolysis stops
...
You have to knead the dough to get all the yeast inside/
anaerobic respiration – no oxygen inside
...


o

Our body doesn’t do Alcohol Fermentation!

o
-

Wine (made from grapes)
...
The grapes are
put into an air tight barrel (no oxygen)
...
Now they have to use
fermentation because they have no oxygen
...
They make 2 ATP and 2NADH but they can’t go to the
Krebs cycle which means they don’t have more NAD+
...
This involves the conversion of pyruvates to 2 Acetylaldehyde (2 2-carbon chains) by releasing CO2 turning the drink fizzy
...
Now
you end up with NAD+ and 2 Ethanol which is the product of the Acetylaldehyde and the H
...
All products: 2 CO2, NAD
+, and 2 Ethanol
...
An
Obligate Anaerobe – can only make ATP without Oxygen
...
This happens in bacteria and in
humans
...

o

After the two pyruvates in glycolysis, you make 2 lactic acid
...


o

The acid causes milk to curdle/ solidify/ become sour
...
Muscle cells become oxygen deprived and they cannot do
Krebs or ETC and are forced into Lactic Acid Fermentation
...
So you have to get rid of it when you
are in Oxygen Debt – after your body have been making ATP without 02
...
The lactic acid is
now sent to your liver and it converts the acid back to pyruvates so they can go
straight to Krebs
...
Make more cells as organism grows – because cells must remain small ! more cells not
larger cells
...
Cells die – they need to be replaced and some cells are damaged (surgery, cuts …)
Not all cells divide
-

brain cells – only divide during early development

-

muscle cells don’t divide – only fibers

-

Red blood cells don’t divide – your bone matter makes more blood cells but the
cells themselves don’t divide
...

Bacteria – simple cell division
-

Easier, only one cell, no organelles

-

DNA is floating around (no nucleus) – most important replication

-

1 circular large Chromosome (we have 46 – 23 from each present)
o

-

It is twisted in order for it to fit in cell (spaghetti form)

Binary Fission – splitting it two in bacteria – in order for reproduction (not human
reasons)

Steps of Cell Division in Prokaryotes
-

Chromosome has an Ori – origin of replication
...


-

You replicate the Ori (now you have 2) and the replication of the cell starts in one part
and goes around at the same time on different sides so that they can meet on the
other side
...
One Ori with DNA goes to one end of the Cell
and the other at the other end
...


-

The replication finishes
...

The cell membrane pinches in the middle which creates 2 identical daughter cells
...
Each strands of DNA/
chromatin have hundreds of Genes – specific DNA sequence
...
Genome – all of the cells genetic info (eye color, hair color,
skin …
...
A Nucleosome is the DNA that gets
rapped around the Histones or “beads on a string”
...
Now they can split evenly at the Centromere which is the part
of the chromosome where the two strands are attached
...


Interphase – 3 stages that prepare cells to divide
1
...
S (synthesis) – replication of DNA ! 46(2) = 92 strands of DNA (chromatin)
3
...
Its job is to make a Mitotic Spindle (spindle fibers) after adding the
tubulin
...

Mitotic spindle begins to form and the DNA condenses ! Chromatin to
Chromosomes
...

Centrosomes move to opposite poles and the mitotic spindle are fully formed
and also move to the opposite poles
...
On the chromosomes, there is
a Kinetochore Protein – a complex of proteins where the mitotic spindle
attaches to the 2 identical sister chromatids
...
There are 2 spindle fibers per each Chromosome
...


o

Anaphase – breaking/ separating the Chromosomes
...
Now 2 sister chromatids split in half and
each half is one chromosome
...
Now you 92 chromosomes in the cell
...
They pull
against each other to contract
...
It is called Cleavage Furrow
...

They have vesicles filled with proteins + Carbohydrates (came
from Golgi)
...
The vesicles fuse together forms the cell
plate which is then formed into the cell wall
...


CANCER – uncontrolled cell division (growth)
-

Cell Cycle Control – checkpoint – to know is anything is wrong (point in cell cycle
where you stop and check for mistakes) – happens in G1/ G2/ Mitosis –
G1 - Check for external (outside cells) signals ! G0
1
...
Environmental conditions – temperature, amount of nutrients
G2 – proofreading/ checking for errors in DNA replication
...
Enzymes check
and fix errors
...

-

if you do have a mistake then:
1
...
Repair the cell so cell division can proceed
...
G0 – non-dividing state (hibernation) – muscle cells, nerve cells and brain
cells " constant G0 state
...
The cancer ignore checkpoints
! the proteins are not working and the cells can continue to divide
...
Immortal (can’t die)

2
...
– Tumor – clump of cells (abnormal), Benign Tumor – not
harmful tumor – doesn’t invade any organ
...

3
...

Metastasis – cancer cells travel from one site to another (spread throughout the body)
In 1951, Henrietta Lacks had Cervical Cancer and had her tumor removed – the tumor is living
till today/ immortal
...

Cancer, even with a mistake, will continue to grow
...
Chemotherapy – very strong drugs that target actively dividing cells (Cancer, hair
cells)
...
Taxol – prevents microtubules from breaking apart from each other (can’t
continue growing after Anaphase)
2
...
Surgical removal of Tumor
Lab
Whitefish Blastula – embryotic cells are actively dividing (growing)
Onion cell – scallions
Looking for nucleus with nucleoli in it
...

46 ! meiosis ! 23 gametes

Diploid – 2 sets of chromosomes (2N) – N = 1 set of chromosomes (1 maternal and 1
paternal) – 46 chromosomes – every cell in your body (somatic) except your Gametes
Haploid – N – 1 set of chromosomes, in humans = sperm or egg – 23 chromosomes
Asexual reproduction – mitosis (all offspring are identical to parents)
Sexual reproduction – meiosis (23 from sperm and 23 from egg - haploid) ! (46 –
diploid) variation in offspring
Autosomes – 1! 22 chromosomes – do not determine the sex of the child - 44
Sex Chromosomes – the 23 chromosome - determines the sex of the child (x - girl or y
- boy) - 2
Homologous Chromosomes – the 2 chromosomes (same chromosome from father +
mother) that have same size, same # of genes, same type of genes except for a slight
variation (green + brown eyes)
Gametes – have half the chromosomes of the germ cell and are haploids
...
Meiosis doesn’t undergo any more divisions
...
Interphase – only proceeds Meiosis I
a
...
S – DNA replication
c
...
Meiosis I
a
...
Nuclear envelope/ nucleolus disappear
ii
...
23 father or mother
chromatids – copied during S phase making 46 of each, which then
condenses to 23 chromosomes from each father and mother
...

iii
...
Synapsis is the process of coming together to form a tetrad
...
Crossing Over is when the Genetic material is exchanged between
Homologous chromosomes which is one of the causes of Genetic
Diversity
...
The strands get exchanged, they aren’t identical
anymore, it always happens and the chromosomes are no longer made
up of identical sister chromatids
...
Spindle forms
vi
...
Metaphase I
i
...
There is one spindle
per chromosome and each spindle is attached at the centromere by the
Kinetochore protein
...
Independent Assortment – the order of which the tetrads line up on the
metaphase plate – the order matters
...
It will
determine which genes end up in which gamete
...
Anaphase I
i
...
Each
chromosome has 2 non-identical sister chromatids
...

d
...
Nuclear envelope and nucleolus reform
...
Most species skip Telophase
because it will be undone when splitting again
3
...

Genetic Variation
1
...
Independent Assortment in Metaphase I ! 8 million possibilities
3
...
During Puberty
Meiosis proceeds
...
You never finish Meiosis unless your
eggs are fertilized
...
They have unequal cytokinesis and produce 3 polar
bodies and one huge egg which is the only egg that can be fertilized
...


Stem Cells
-

Cells that don’t divide like nerve, muscle, red blood cells
...
Embryonic Stem Cells – found in embryo, it can divide into any type of cell
...

2
...
He worked with 2
strains of Streptococcus pneumonia
1
...
Avirulent – non-disease causing (R strain – rough), it lacked a smooth capsule that
would surround the bacterial cell wall
...
Grew R+S bacteria
2
...
Injected S bacteria into mouse ! it died
4
...


Heat inactivated S strain and mixed with R strain killed the mouse
...
The R cell was transformed into
Virulent bacteria
...
He did this in Vitro (in a test tube)
...
He systematically took each content out of the cell to see if the cell
would transform
...
Inactivated heat killed S cells and adds Rnase (enzyme) to extract RNA
...
The R cells transformed into S so we learn that RNA is not the
transformation factor
...
Protease ! proteins – transforms
3
...
Carbase ! carbs – transforms
5
...

A virus is made of a protein head, a long coiled body and a bunch of tail fibers that help the
virus land on a cell in order to inject its genetic material
...
They used radioactive material and looked for the unique
thing in each protein and DNA
...
They substituted sulfur with S35 which made the protein head
radioactive
...
They mixed both
batches with bacteria cells and he cell that was radioactive indicated which (protein
head or DNA) was the genetic material
...


1950 – Chargaff’s rule (complementary bases …)
R
...

Watson + Crick made the shape of the double helix
...
He then took this information and Chargaff’s rule and believed that
DNA was a double helix
...
5 Prime is the side of the strand where you have a phosphate on the 5th
carbon of the sugar
...

Prokaryotes – one central circular chromosome and has one origin of replication (ori)
Eukaryotes – more chromosomes (46 for humans) and are long and stringy
...

Bacteria Replication
On the circular chromosome, there is one Ori
...
4
...

Replication in Humans
You have several oris per chromosomes (also bidirectional)
...

Steps of Replication:

1
...
Helicase – enzyme that breaks the H-bonds
between
...

2
...
Single-strand Binding proteins – an enzyme that binds to separate DNA strands
and prevent them from rebinding to their complementary strand
...
Topoisomerase – prevents strands from over-twisting
3
...
DNA polymerase – enzyme that adds bases
...
It only adds nucleotides to a pre-existing 3 prime end and uses
energy
...

b
...
DNA polymerase can then add
nucleotides to the RNA primer
...

Okazaki solves the problem by putting many RNA primers that can connect in a
downward motion even though replication is still moving upwards
...
RNA primers are removed, a different DNA polymerase fills in the gaps
...
If there is a mistake in DNA replication (in G2), the
mistake gets excised and is replaced with the proper base via repair enzyme
...
Telomeres are the
regions of DNA at the “ends” that cannot be replicated ! no 3 prime end for
DNA polymerase to attach to
...
Some cancer cells are able to produce Telomerase to
extend their life
...


Steps for Transcription
1
...
Upstream = before promoter, Downstream = after
promoter
...

2
...
Sense strand the strand we don’t replicate, Anti-sense
strand we replicate for RNA
...
RNA polymerase is in charge of adding these bases
...
Termination – the RNA polymerase reaches the Terminator sequence (stops)
a
...
New mRNA falls off the DNA template
c
...
Cap – modified GTP which
protects the 5’ end
...

Translation
mRNA is in the form of nucleotides and to make it into proteins we need amino acids
...
Every triplet codes for one AA
...

Redundancy No Ambiguity – there are many different codons that can code for the same AA,
but every codon only codes for a single AA
...
Stop – UAA, UAG, UGA
-

MRNA leaves the nucleus by the nuclear pores and enters a ribosome (either free or
bound)
...


-

TRNA – contains an anti-codon (complementary to mRNA)
...
Each codon has its own tRNA
...
Silent Point Mutation – mutate a single nucleotide which does not change the AA !
final protein is unchanged
...
Missense Point Mutation – a single point mutation that changes AA ! potentially the
entire protein
...
Nonsense Point Mutation – a single point mutation that causes a premature stop
codon
...
Frameshift Mutation – when you insert or delete a nucleotide that causes a shift in
the nucleotide chain
...
Can also cause a
premature stop codon
...
Removing or adding codon – remove or add an entire codon/ AA
...

Pea plants are ideal for Genetics because:
1
...
Easy to grow
3
...
Self-pollinate or cross-pollinate
o

Self = egg and sperm came from the same flower

o

Cross = egg and sperm came from different flowers

Stigma – female reproduction organ
Stamen – male reproduction organ which makes Pollen (sperm)
Mendel castrated the stamen so that he can manipulate the mating by adding different
pollen
...
Based on the offspring you determine the
genotype of the parent
...


Law of Segregation – each organism produces gametes, each pair of alleles is separated
randomly and each gamete has an equal chance of receiving either one of the alleles
...
Then, self-pollinate and get
all the possible gametes
...


Law of independent assortment – during gamete formation the alleles of each gene
separate independently
...
But,
if two genes are on the same chromosome and close to each other, they will be inherited
together
...

Gene linkage – distance of genes on chromosomes
Beyond Mendel
1
...
Neither allele is dominant
...

2
...
–
found in blood type
3
...

Heterozygote means you carry the gene for the disease yet you are unaffected
...
same thing goes for Tay-Sachs, Cystic fibrosis …
-

Tay-Sachs – a dysfunctional protein (Hex-A) causes an accumulation of lipids in the
brain
...


Dominant inherited – either you have the disease or not, you can’t be a carrier - 6 fingers,
Huntington’s disease (melts away your brain), Achondroplasia (dwarf) …
Recessive – neither parents have to have the disease but must carry it
Dominant – one parent must have the disease
Carriers for Tay-Sachs:
-

Organismal level – you can’t see you are a carrier

-

Biochemical Level – can see the difference – the phenotype is incompletely dominant
– healthy + unhealthy protein

-

Molecular level – the alleles are both expressed

Pedigrees
-

When you have a 3rd generation with a disease and its parents don’t, then it’s a
recessive disease
...

The wild type was red eyes
...


Morgan took a red true breeding female and mated it with the white eyed male
...
He then mated those offspring’s with each other and the result
was that the females were all red eyed but 50% of male were white eyed
...

Nondisjunction – during Meiosis I or II, the chromosomes don’t separate evenly
-

There should be four haploid cells, but you might get one diploid, 2 haploid and one
empty
...
Automatically
a girl
...
21 – you have down syndrome

-

18 – worse down syndrome

Monosomy – 1 copy of chrom
...


Genetic Testing
-

Fetus
o

Amniocentesis (14-16 weeks in utero)
▪
▪

Extract amniotic fluid

▪

Cells of fetus floating around

▪
o

Insert large needle through belly button

You may lose a baby 1/200

CVS
▪

Chorioic villi sampling – 8-10 weeks pregnancy

▪

Take sample of placenta

▪

Losing baby 1/100

Evolution
The earth was created 4
...
There was a lot of cosmic debris
...
About 300 million years later it began to cool down
...

We are made up of organic molecules – carbs, lipids, nucleic acids and proteins
...
1953, Miller + Urey (experiment)
They took a glass of water and the gasses and boiled it
...
The gasses cooled and became a

liquid
...
They were able to take non-organic chemicals and form the basis of life
...
The UV rays
destroyed a lot of the ammonia + methane
...

2
...
In the crater they found an organic
soup
...

3
...

Lipids + water ! Lipids go to top of ocean and form these fat droplets
...

Heredity
Ribozymes – RNA that acts as an enzyme (first RNA), that time RNA was responsible for
Heredity – now it’s DNA
...
5 billion years ago
...
These
organisms became Photosynthetic by producing its own energy
...
Cyanobacteria – blue green
bacteria – the first photosynthetic bacteria that caused the first mass extinction
...

Ozone Layer – was formed by the new oxygenated atmosphere
...
They started taking on “specialized functions” with every bacteria having
different skills
...
This happened in the
Cambrian Period
...
Rain/ heat/ cold ! breaks apart rocks into sediment
2
...
Sediment settles at bottom of the sea as clay/mud

4
...
More sediment falls on top
...
Fossil Record is incomplete because you need all these conditions
to have them and not all organisms get fossilified when dead
...
Physical structure
2
...
Geography
4
...
Relative Dating (not exact)
o

Strata – different layers of rock where fossils are found

o

Index fossils – fossil found in more than one area – marker to compare fossils in
different areas
...
Absolute dating
o

Specific age + radiometric dating (half-life, carbon-14 …)

Mass Extinction
End of one era and the beginning of the next era (ex: Jurassic)
...
99% of all species are extinct now
...

He believed there were 3 patters of diversity among species;
1
...
Species vary locally – different types of animals in one area
3
...
Galapagos finches were different than mainland finches (beak
shape + size, different diet)
...


-

Pressure of new habitat makes you eat certain foods with the modification of the
Genetic beaks
...

Darwin’s Influences
1
...
Lyell explained the events that happened in the past in terms of events
occurring in the present (volcanoes + earthquakes) = Uniformitarianism
b
...
Lamarck – said species change over time
a
...
Disuse – the less you use something the less useful it would be
c
...
Thomas Malthus – 1798 – Economist
a
...
Exponential graph – exponential growth of population vs
...
Human population growth is kept in check: Disease, war and famine
d
...
The natural world environment will keep the number of
organisms in check
...
Artificial selection – breeders, humans choose desired traits and breed those animals
expressing those traits
Natural Selection: Darwin’s theory according to 4 influences
1
...
Variation – in offspring due to sexual reproduction – Genetics
3
...
Heritable trait that gives them (the fittest) a selective advantage to survive

b
...
Factories release soot + smoke that makes the trees turn black,
white moths now are not able to survive and die
...

4
...
These traits that let them do this gets passed on to future generation
...
Biogeography
a
...
Similar environments shape the characteristics or traits of organisms even
though they are not closely related
c
...
Fossils
a
...
Radioactivity – organisms dating slowly and gradually over time
c
...
Developmental Biology
a
...
Analogous structures – structures all have common function yet no recent
common ancestor
4
...
In early stages of development, Embryos are almost identical
5
...
Anatomical features that no longer serve a purpose (appendix, tail bone)
Classification – system of organizing organisms into categories
Natural selection leads to Evolution which leads to the formation of a new species
Speciation – formation of a new species
1
...
Small gene pool forms an entire population
2
...
Natural things cause this (rivers, mountains, earthquakes
…)
...


3
...
Temporal Isolation – time of day/ month/ year is different for mating
Coevolution – evolving together
...

Taxa – group of organisms with common characteristics
Taxonomy – study of similarities and differences in physical appearances
Linnaeus used the Latin system called Binomial Nomenclature (system of naming things using
2 names)
...
Domain – has the most organisms and share the fewest characteristics (biggest part on
top)
...

2
...
Phylum
4
...
Order
6
...
Genus
8
...
The first name will be like a family name (shared
with a bunch of other similar animals) & will be the Genus and the second name is like
your first name (showing exactly which organism you are) & will be the species
...

Cladogram – links organisms from a common ancestor
Node – speciation event that causes new species
...
We can compare different sequences because it is written in the universal
genetic code

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