LS 15 PHELAN UCLA FINAL EXAM
dawn ashworth and lynda mann murders - ANSWER one man confessed only to the
second murder
alec jeffreys investigating how to test for DNA - 1985
found that perpetrators of the crime were the same, but it wasn't the guy who
confessed
got voluntary blood and saliva samples
colin pitchfork
fingerprint for crime identification - ANSWER has been in use for hundreds of years
good for property ones
turn into numerical code based on these parts
why are we interested in dna fingerprinting? - ANSWER real fingerprints not left
behind in many crimes
they are essentially unique
real fingerprints are - ANSWER entirely unique
dna fingerprinting uses - ANSWER solve unsolvable crimes
resolve paternity issues
can prove innocence of people unjustly convicted
immigration
dna is - ANSWER a long sequence of letters that carry the info of how to build
molecules for the body
A or T, G or C - ANSWER match up
how much "spelling" difference is there between individuals? - ANSWER 99.9% of it
exactly the same
different enough: 3 M diff base pairs
on average, indiv differ in their dna sequence at - ANSWER 0.1% of their bases: 3M
differences out of 3B base pairs
blood - ANSWER can isolate cells that came from perpetrators, get to repeating
parts, indication - random population to compare to
short tandem repeats (STRs) - ANSWER repeating units, usually 4-5 nucleotides
long
diff alleles may repeat different amount of times
call it a locus: location on chromosome
noncoding - doesn't code for any product, protein, built, etc. "junk dna"
nucleotides - ANSWER A, T, C, G
,supposed there are 10 alleles for str 1, each with the same frequency in the
population. what is the likelihood that a random person has the same genotype as
the perpetrator's DNA found at a crime scene? - ANSWER 1/100 (why???)
homozygous - ANSWER has to inherit same allele, same for STRs
10, 10 x 12, 14 not homozygous if 10 12 or 10 14
more questions about possible STR allele combos - ANSWER cross them like a
punnett suqare still
for an str locus -> many (2 or 3 dozen or even more!) - ANSWER alleles exist within
the population, but each individual can only have two of them
many individuals have different - ANSWER STR loci: at different pace and how many
of them
creating a DNA fingerprint - ANSWER 1. dna fragment containing each STR region
is amplified. results in huge numbers of those fragments
2. fragments separated by size, using electrophoresis
3. str region is stained on gel
US combined DNA index system (CODIS) database includes - ANSWER 20 STR,
scattered across human genome.
human paternity testing - ANSWER analyzing 1 locus
what do the bands represent?
- represent fragment that's been cut on each side, amount of distance related to how
many repeats there are.
which pair of people are the parents of each?
dna fingerprinting challenges and controversies - ANSWER 1. overlap of strs
2. how many strs should we compare?
3. how likely is a match? multiply 4 probabilities of matching 1 band by each other. ->
can juries understand this?
4. are there subpopulation differences? does it matter if every person within a
subpopulation has the same alleles for an str? why?
5. do humans make mistakes?
6. how sure do we wanna be?
what are some things that living systems need? - ANSWER fuel
1. raw materials for growth
2. energy to do things that won't happen spontaneously (ex: walking, growing new
tissue, adding muscle mass, reproduction)
fuel comes from - ANSWER energy stored in chemical bonds
who creates energy initially? - ANSWER photosynthetic organisms
how to release energy - ANSWER breaking bonds that are lower
, photosynthesis - ANSWER put energy in from the sun, building up bonds in carbs
that are later converted
photosynthesis is like - ANSWER eating in reverse
what is doing "work" - ANSWER breaking bonds and reforming new bonds releases
energy that can be harnessed to do "work"
how do we power machines? - ANSWER gasoline and many other fuels
but for our purposes: break the bond, form a bond at lower energy, harness extra
energy to do stuff
hydrocarbons - ANSWER molecules with chains of carbon and hydrogen atoms (5-
12 carbons)
car engines - ANSWER combust hydrocarbons, forming new bonds, releasing
energy that can be harnessed
examples - ANSWER heptane (gasoline) has 16 Hs, methane has 4 Hs, propane
has 8 Hs
biofuels - ANSWER are natural oils from plants, or sugar/starches modified into
ethanol
still Hs connected to carbon that are going to combust somehow. they have different
outcomes
lipids - ANSWER not water soluble
major storehouses of energy
good insulators
for storing and generating useful energy
molecules in dirt have chemical bonds. why don't we eat dirt? - ANSWER it doesn't...
major types of lipids - ANSWER fats/triglycerides
phospholipids
steroids
storing extra energy - ANSWER liquid is the most efficient form
ex: seals, sumo wrestlers
lipids in our diet - ANSWER usually in the form of fats and triglycerides
triglyceride example - ANSWER tristearin: triglyceride derived from 3 stearic acid
molecules, obtain from animal fats and some plant fats, solid at room temp
what's the difference between saturated and unsaturated fats? - ANSWER depends
on whether there are double bonds in hydrocarbon tail
saturated fats can pack together densely with the double bond. enzymes less likely
to get in there and more likely to shove it into a fat cell
in unsaturated fats, the fatty acid tails "bend out", they can't pack
dawn ashworth and lynda mann murders - ANSWER one man confessed only to the
second murder
alec jeffreys investigating how to test for DNA - 1985
found that perpetrators of the crime were the same, but it wasn't the guy who
confessed
got voluntary blood and saliva samples
colin pitchfork
fingerprint for crime identification - ANSWER has been in use for hundreds of years
good for property ones
turn into numerical code based on these parts
why are we interested in dna fingerprinting? - ANSWER real fingerprints not left
behind in many crimes
they are essentially unique
real fingerprints are - ANSWER entirely unique
dna fingerprinting uses - ANSWER solve unsolvable crimes
resolve paternity issues
can prove innocence of people unjustly convicted
immigration
dna is - ANSWER a long sequence of letters that carry the info of how to build
molecules for the body
A or T, G or C - ANSWER match up
how much "spelling" difference is there between individuals? - ANSWER 99.9% of it
exactly the same
different enough: 3 M diff base pairs
on average, indiv differ in their dna sequence at - ANSWER 0.1% of their bases: 3M
differences out of 3B base pairs
blood - ANSWER can isolate cells that came from perpetrators, get to repeating
parts, indication - random population to compare to
short tandem repeats (STRs) - ANSWER repeating units, usually 4-5 nucleotides
long
diff alleles may repeat different amount of times
call it a locus: location on chromosome
noncoding - doesn't code for any product, protein, built, etc. "junk dna"
nucleotides - ANSWER A, T, C, G
,supposed there are 10 alleles for str 1, each with the same frequency in the
population. what is the likelihood that a random person has the same genotype as
the perpetrator's DNA found at a crime scene? - ANSWER 1/100 (why???)
homozygous - ANSWER has to inherit same allele, same for STRs
10, 10 x 12, 14 not homozygous if 10 12 or 10 14
more questions about possible STR allele combos - ANSWER cross them like a
punnett suqare still
for an str locus -> many (2 or 3 dozen or even more!) - ANSWER alleles exist within
the population, but each individual can only have two of them
many individuals have different - ANSWER STR loci: at different pace and how many
of them
creating a DNA fingerprint - ANSWER 1. dna fragment containing each STR region
is amplified. results in huge numbers of those fragments
2. fragments separated by size, using electrophoresis
3. str region is stained on gel
US combined DNA index system (CODIS) database includes - ANSWER 20 STR,
scattered across human genome.
human paternity testing - ANSWER analyzing 1 locus
what do the bands represent?
- represent fragment that's been cut on each side, amount of distance related to how
many repeats there are.
which pair of people are the parents of each?
dna fingerprinting challenges and controversies - ANSWER 1. overlap of strs
2. how many strs should we compare?
3. how likely is a match? multiply 4 probabilities of matching 1 band by each other. ->
can juries understand this?
4. are there subpopulation differences? does it matter if every person within a
subpopulation has the same alleles for an str? why?
5. do humans make mistakes?
6. how sure do we wanna be?
what are some things that living systems need? - ANSWER fuel
1. raw materials for growth
2. energy to do things that won't happen spontaneously (ex: walking, growing new
tissue, adding muscle mass, reproduction)
fuel comes from - ANSWER energy stored in chemical bonds
who creates energy initially? - ANSWER photosynthetic organisms
how to release energy - ANSWER breaking bonds that are lower
, photosynthesis - ANSWER put energy in from the sun, building up bonds in carbs
that are later converted
photosynthesis is like - ANSWER eating in reverse
what is doing "work" - ANSWER breaking bonds and reforming new bonds releases
energy that can be harnessed to do "work"
how do we power machines? - ANSWER gasoline and many other fuels
but for our purposes: break the bond, form a bond at lower energy, harness extra
energy to do stuff
hydrocarbons - ANSWER molecules with chains of carbon and hydrogen atoms (5-
12 carbons)
car engines - ANSWER combust hydrocarbons, forming new bonds, releasing
energy that can be harnessed
examples - ANSWER heptane (gasoline) has 16 Hs, methane has 4 Hs, propane
has 8 Hs
biofuels - ANSWER are natural oils from plants, or sugar/starches modified into
ethanol
still Hs connected to carbon that are going to combust somehow. they have different
outcomes
lipids - ANSWER not water soluble
major storehouses of energy
good insulators
for storing and generating useful energy
molecules in dirt have chemical bonds. why don't we eat dirt? - ANSWER it doesn't...
major types of lipids - ANSWER fats/triglycerides
phospholipids
steroids
storing extra energy - ANSWER liquid is the most efficient form
ex: seals, sumo wrestlers
lipids in our diet - ANSWER usually in the form of fats and triglycerides
triglyceride example - ANSWER tristearin: triglyceride derived from 3 stearic acid
molecules, obtain from animal fats and some plant fats, solid at room temp
what's the difference between saturated and unsaturated fats? - ANSWER depends
on whether there are double bonds in hydrocarbon tail
saturated fats can pack together densely with the double bond. enzymes less likely
to get in there and more likely to shove it into a fat cell
in unsaturated fats, the fatty acid tails "bend out", they can't pack
