BIOL-1506EL Final: BIOL-1507 - Exam Review
27 Jun 2018
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BIOL-1507 - Exam Review
Life:
-Anything considered alive is able to reproduce
-20 000 years before present was the end of the last pleistocene ice age
-when this ice melted, it covered most of Canada and the USA, which lead to the ice
age, all these scientific events influence the variety of life we have today
-Our prebiotic earth has no living life, but just elements life H, CO2, N but no O2
-There was oxygen tied into chemical reactions and compounds
-The theory states that there was energy sources (ex. lightning, thermal vents, uv
light) that would hit random objects and cause random reactions to occur
-This would create many random things like lipids, sugars, amino acids, acids, etc
-This lead to the random production of replicator molecules, which would float around
and catch other molecules and replicate those molecules
-RNA was the first replicator molecule, with only 80% accuracy when replicating itself,
which increased the chances of mutations (As well as the number of molecules
replicated exponentially)
-95% of mutations are detrimental and will decrease the ability of that molecule to
survive
-5% of mutations are actually beneficial and would increase the chances of
reproduction and therefore survival of that molecule
-DNA was created by 2 RNA’s bonding together
-DNA has a 99.9999999% accuracy when replicating, therefore much less mutations
occur
-Influenza, aids, herpes, and others, are all RNA which makes it difficult to find a cure
for these
Proof of theory of natural selection:
-They replicated these reactions in lab experiments
-They found that all 20 amino acids (building blocks of proteins) were created by
running electricity through objects, these are found in all living organisms
-They also created sugars (most organisms use glucose) which is another building
block for living organisms
-They also produced lipids (fats and oils) which are essential to all living organisms
-Fats are needed for successful reproduction
-They also produced purine and pyrimidine, which are found in nucleic acids )RNA,
DNA) which are also completely essential in any living organisms
-All of these are found in living organisms which is proof of life beginning in this way
Timeline of Humans:
-4 500 million years ago was the origin of life (estimate)
-4 000 million years ago was the origin of life on earth
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-began as prokaryotes (meaning first cell), which are single cell organisms
-bacteria are a type of prokaryotes
-another prokaryote was blue green algae (cyan bacteria)
-this allows more oxygen to be present in the environment, as a waste product
that we humans use
-this occurred before any oxygen needing animals were on earth
-3 500 million years ago we have the oldest fossils
-found in Australia
-2 500 million years ago we got oxygenated atmosphere
-2 000 million years ago was the origin of eukaryotic cells
-1 000 million years ago was the origin of multi cellular organisms
-500 million years ago we had plants colonizing land, and animals that began in the
sea
-63 million years ago we had the extinction of dinosaurs
-this landed in the impact area in the Caribbean
-1 million years ago the first humans (humanoids) began on Earth
-evolution of the homo sapien (us)
-this historical background began in Africa (origins are African)
-homo erectus were the first of our kind, which moved around and out of Africa in
groups of small numbers
-Homoerectus moved into central Europe, which also had homo neanderthalensis
-In central asia, there were homo denosinova
-In indonesia there were homo foresicnus
-40 000 years ago we moved to the european area, which lead to the extinction of all
other subspecies, although we still cary some of the genes from all of these sub
species
-12 000 years ago, there were no humans in the north/south american region, which
was during the end of the pleistocene ice age, as his area was covered in ice before
the ice age
-first nation people arrived through BC or Alberta to Canada and the USA
-1 000 years later they moved to Cuba in South America
Natural Selection
-some selective factors (or ecological parameters) are:
-temperature
-salinity
-pH
-Viroids: naked RNA molecules
-several hundred nucleotides long
-Virus: obligate inter cellular parasites
-they infect cells and make the cell their environment (ecology) where it will
reproduce and spread
-made up of RNA or DNA
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-T-4 Bacteriophage
-this is a DNA virus, and DNA is very active while replicating and very successful
-Influenza Virus (like the 24 hour flu)
-Replicator molecules (RNA) (only 80% accurate when replicating, therefore mutation
rate is high)
-produce new vaccines to combat the new mutations every year
-T-4 Bacteriophage reproduction (Lytic cycle or lysogenic cycle):
-Lytic Cycle:
-virus injects its piece of DNA into the cell
-now viral DNA is a part of the DNA of the host cell
-it will take over control of the host cell
-all resources will be used to replicate viral DNA
-then the host cell will burst and the virus will spread
-Lysogenic Cycle
-virus injects its piece of DNA into the cell
-now viral DNA is integrated into the DNA of the host cell
-then the cell will go through cell division (fission)
-when it replicates itself, it will be replicating the infected DNA with
the viral cell
-Therefore viruses are very successful organisms in surviving and
replicating
-the selection of which way it goes depends on the condition of your
immune system
-your immune system will detect foreign cells that aren't yours and kill
off these cells
Prokaryotic Cell:
