Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
91 Cards in this Set
- Front
- Back
|
Phylogenetic Trees
|
a diagram that depicts the evolutionary history of a group of organisms
|
|
|
Evidence for single origin of life on earth: that all species are descended from a single common ancestor at the root of a family tree of all organisms—the tree of life
|
1)Central Dogma (DNA to RNA to Proteins in all life forms)
2)Same genetic code used by all life forms 3) Same 20 essential amino acids in all life forms 4)Some common metabolic pathways |
|
|
three main domains in the tree of life using rRNA sequence:
|
bacteria, archea, eukarya
|
|
|
Why use rRNA?
|
Looks at rRNA because you want changes to be at a constant rate. Plus you want the sequence to be present in all organisms (all cells have ribosomes).
|
|
|
Taxonomic Levels by whom?
|
k(kingdom)
p(phylum) c(class) o(order) f(family) g(genus) s(species) Linnaeus |
|
|
describe characterisitcs of out taxonomic levels:
animalia, chordata, mammalia, primates, homonidae, homo, sapiens |
Animalia: breathe, feed, and breed
Chordata refers to those with backbones. Mammalia: mammary glands, warm-blooded Primates: mixed order: large brains, 3D vision, extended period of parental care, etc Hominidae: eliminates monkeys-only humans and great apes. Homo: us and extinct relatives sapiens: us |
|
|
How do chromosomes compare between humans and apes? How did we get 46?
|
46 vs 48
chromosome2: Fusion in out telomere sequences and resulted and deactivation of one centromere since all eukaryotic chromosomes have a single centromere (as well as telomeres at their ends. |
|
|
We have extra copies for synthesizing ___ which is needed for brain development. These changes might have helped our brain evolution
|
B-12
|
|
|
Humans and chimpanzees are 9_.4% - 9_.8% identical.
|
8, 8
|
|
|
_% difference between monkeys and us and _% between us.
|
1.4, .2
|
|
|
But…even though there is only a small difference in percent, this is spread among many genes so that __% of chimp proteins differ from human proteins
|
84%
|
|
|
__% of changes in structural genes of humans and chimps are product of natural selection
|
20
|
|
|
Based on the microarray of mRNA of from humans, chimps, rhesus: rank the most differece in gene sequences to the least: brain, liver, blood
|
brain, liver, blood
|
|
|
What is FOXP2? When did ours evolve? How was it identified?
|
-A transcription factor expressed in the brain expressed early in fetal development. Perhaps it starts cascade of transcription that affects brain development.
-within last 200K -Identified due to an inheritable speech impediment in humans. Includes difficulties with comprehension Brain-imaging reveals abnormalities in language related areas |
|
|
australopithecines/autralopithecus broke of from apes then Paranthropus (robust "..") broke off and Homo continued. Then from homo neanderthals broke off and the rest evolved to us!
|
yeah
|
|
|
Earliest form of hominidae that has been found
|
Australopithecus afarensis (lucy)
3.9-3.0 MY |
|
|
Bipedalism seems to have evolved as our ancestors...
Erect posture allows hominins... |
...left dense forests for grasslands and open woodlands.
...to keep cool. |
|
|
what are the two Main theories of the geographic origin of modern humans and describe each (what does it imply and what's it supported by).
|
Multiregional model, Out of Africa model
-MULTIPLE origins of modern humans from regional variants of Homo erectus; interbreeding; Supported by some fossil evidence (Pekin man and modern chinese); Imply that the ancestor of all modern human populations would be as old as Homo erectus. -SINGLE and RECENT origin of modern humans in AFRICA 100-200 KYA; no interbreeding; Imply that Homo sapiens outcompeted other archaic forms and led them to extinction; Supported by the majority of genetic evidence |
|
|
neanderthal versus humans
|
we have higher brain case, narrow nasal aperture, shorter collarbone, cylindrical not conical ribcage, longer trunk, narrow not flaring hip bones, thin-walled limb bones, slender hand bones, smaller joint surfaces, and longer legs.
|
|
|
Neanderthals were restricted to ___ and ____. “Modern” humans- earliest in ___, then ____, then ___ and ___.
|
europe and western asia; africa, western asia, europe and eastern asia.
|
|
|
What genetic tools do we have to resolve the question of the relationship of Neanderthal to modern humans? because (3):
Additional benefit of mitochondrial DNA is that: |
Mitochondrial DNA and Y chromosome
-don't recombine (mix mom and dad's) so it's useful to trace lines of descent directly (because only received from mother); have high mutation rate so useful to reconstruct evolutionary history; Matrilineal or patrilineal souseful to disentangle sex-specific migration patterns -They are present in large numbers in each cell, so fewer samples are required |
|
|
What is The Feldhofer Neanderthal Study? What did it reveal and conclude?
|
extract DNA, amplify and compre to humans and chimps
-Revealed 27 nucleotide differences; Average # of bp differences in human pops is 8/360 and that neanderthals are different species that broke off earlier than predicted (500-600K). |
|
|
Neanderthals fall... and what were some added controls to the conclusion?
|
outside of the human range of variation
-usuing more neanderthals, and and using DNA from early human. |
|
|
Neanderthals and human genomes are at least __._% identical
|
99.5
|
|
|
what did the mitochondrial eve study show?
|
using average # of nt diff they figured date was 171,500. Date would have to be much older for multi model as it would represent the common ancestor of Homo erectus rather than of Homo sapiens.
. |
|
|
in tree, what does more variability in africa reveal?
|
More variety in Africa (red) meaning they must have existed for a long time in Africa and spread out much later.
|
|
|
Svante Paabo and Edward Rubin did what? What are three possible technical issue in their study?
|
Recent Neanderthal genomic DNA sequencing (took DNA in both studies from a bone discovered in a cave in Croatia)
-1)Contamination in sample (It is very easy to amplify contaminating human DNA and their similarities would make it difficult to differentiate the two); (2)Contamination with bacterial/fungal DNA is also a problem since bacteria infect the dead carcass;(3)Degradation of DNA over time |
|
|
tritium
|
hydrogen atom with two neutrons; tritium is unstable and decays at a certain rate over time
|
|
|
describe experiment that discovered that chromosomal replicationj occurs in the S-phase. (4)
|
1) feed radioactive thymidine to cells growing in culture
2)after 30 min wash unincorporated thymidine out of culture 3)spread out cells and expose to phtographic emulsion 4) only interphase cells are labeled with in. |
|
|
Gaps allow cell to...(ex's)
|
continue with preparations for cell replication: making more organelles, manufacture additional cytoplasm. They allow the cell to complete all the requirements for cell division other than chromosome replication.
|
|
|
S phase can be measured
by ____ incorporation. Mitosis can be determined ____ |
isotope, microscopically
|
|
|
metaphase checkpoint...pass if
why have it? |
all chromosomes are attached to mitotic spindle
-don't want one daughter cell to be short of chromos |
|
|
G1 checkpoint: passs if...
___ cells do not pass this checkpoint. Protein? What kind of cells would have a problem with G1 checkpoint? |
nutrients are sufficient, grwoth factors are present, cell size is adequate, DNA is undamaged
-mature -p53 -tumor cells |
|
|
G2 checkpoint: pass if...
protein? |
no DNA damage and if chrmosomal replication is succesfully completed. MPF (mitosis-promoting factor)which is blocked if cell not good enough.
|
|
|
cDNA...and then who comes in to play afterwards?
|
the complimentary DNA made from reverse transcriptase
-DNA polymerase which synthesizes the complimentary strand to create the double helix. |
|
|
sticky ends
|
said to be sticky because the single-stranded bases on one fragment are complimentary to the single-stranded bases on the other. As a result, the two ends will tend to pair up and hydrogen bond with one another.
|
|
|
Cells’ own DNA is protected from being cut because ____ So virus that doesn’t have methyl group is __.
|
-the specific sequence of bases that is targeted (recognition site) has methyl (-CH3) groups attached.
-cut |
|
|
Most commonly used enzymes cut DNA only at sites that form _____. Most of the known restriction endonuclease recognize a unique type of ____ DNA sequence. What does this imply about the enzymes?
|
palindromes
palindromic Restriction enzyme = two proteins which read DNA from both directions (each strand) because it’s the same sequence in both directions. |
|
|
extrachromosomal pieces of DNA, which are ___ and can be used as ___.
|
plasmid
self-replicating cloning vectors |
|
|
DNA ligase
|
glues back DNA
|
|
|
cDNA library
|
collection of bacterial cells, each containing a vector with one cDNA from a particular cell type/tissue.
|
|
|
plasmid names begin with
|
lowercase p
|
|
|
Gel Electrophoresis (3)
|
1)DNA fragments produced by specific restriction digestion are separated in an electric field based on their relative molecular size
2)Small molecules move through the gel faster than large ones, hence the distribution is large (top) to small (bottom). 3)The DNA can be detected by staining (colored insert) or, if radioactive, by exposing the gel to a sheet of photographic (X-ray) film. |
|
|
single-stranded fragment of a labeled, known gene that binds to a complementary sequence in the sample being analyzed. They are a way to find one specific sequence in a collection of many different sequences.
|
probe
|
|
|
what is the goal of Dedeoxy sequencing? What do you need?
|
-determine the exact sequence of bases.
-Need many copies of DNA so need PCR. |
|
|
___ is identical to dNTP found in DNA only it lack a ____ group at their 3’ carbon. Sanger realized if this was added it would DNA synthesis.
|
ddNTP, hydroxyl, terminate
|
|
|
Sanger realized that when the fragments are lined up by size, they reveal ___. The net result of Dedeoxy sequencing ___
|
the sequences of bases in the template DNA
-a series of DNA strands, each differing by ONE nucleotide in length. |
|
|
DNA strands melt (____) at high temperature or high pH. Opp =
|
-denature
-anneal, renature, hybridize |
|
|
_____ can be used to identify specific DNA sequences, as only identical sequences will hybridize completely with one another at a specific. temperature, pH, and salt concentration.
What do you need do first? |
-nucleic acid hybridization
-Gel Electrophoresis |
|
|
what is nucleic acid hybridization
|
the part where you incubate filter with solution, containing the labeled probe, which binds to the fragments containing complementary sequences.
|
|
|
what does the blotting help?
|
helps resolve strands because beforehand the're too many and they're all smeared together.
|
|
|
In DNA synthesis the new strand is synthesized in the 5’ to 3’ direction..which means
|
DNA synthesis is continuous on one strand and discontinuous on the other, as the DNA helix is successively unwound during replication.
|
|
|
The enzyme that replicates DNA is called...which needs ___ (short, double stranded template). Who makes the it? wHICH IS A TYPE OF
|
DNA polymerase.
-primer -PRIMASE -RNA polymerase, making the primer anti-parallel to the RNA. |
|
|
Provides a very rapid (hours, as compared to days for the cloning procedures we have been discussing) method for the amplification of specific DNA sequences. So goal is to create many copies of that strand
|
Polymerase Chain Reaction (PCR)
|
|
|
Kary Mullis
|
invented PCR
|
|
|
In PCR use ____ to bracket the region that will be copied/(____)...One ____ is complementary to a sequence on one strand of the target DNA and the other ____ is complementary to a sequence on the other strand so to perform the reaction, a researcher must know the sequences on either side of the region of interest so that the correct ____ can be synthesized.
|
primers
hybridization of primers primer primer primer |
|
|
In DNA synthesis the new strand is synthesized in the 5’ to 3’ direction, which means...
|
DNA synthesis is continuous on one strand and discontinuous on the other, as the DNA helix is successively unwound during replication.
|
|
|
The enzyme that replicates DNA is called
|
DNA polymerase.
|
|
|
This enzyme cannot simply start copying a single strand of DNA. It needs to have a ___(short, double stranded template) from which it starts copying the DNA...which is made by ___, a type of ___
|
primer
primase RNA polymerase |
|
|
Its Goal: create many copies of gene. It’s an in vitro DNA synthesis reaction in which a specific section of DNA is replicated over and over to amplify the number of copies of the sequence.
|
PCR
|
|
|
Describe PCR
|
denaturing, annealing, and extension= one PCR cycle
|
|
|
For PCR a a researcher must know
|
the sequences on either side of the region of interest so that the correct primers can be synthesized.
|
|
|
what are VNTR sequences? What's it used in?
|
variable number of tandem repeats = repeated sequences
Forensics |
|
|
what are the chances of someone sharing the same DNA fingerprint
|
1/10B
|
|
|
animals carrying altered genes
|
transgenic
|
|
|
Green fluorescent protein (GFP): Has what structure? Which forms what which does what? Which relies on the interaction of how many amico acids? What could you do with GFP?
|
-beta barrel: cylindrical tertiary structure
-chromophore -is the part that absorbs light of one wavelength (blue) and emits light of a longer wavelength (green). -3 -fusion protein |
|
|
metastasis
|
the movement of the cancer cells from the primary site of tumor formation to other parts of the mouse’s body
|
|
|
three branches and 1st step to stem cell differentiation
|
ectoderm, mesoderm, endoderm
|
|
|
Why are stem cells promising? (3)
|
-They can replace damaged cells and organs
-They can aid in our understanding of diseases and illnesses -They can serve as a solution to the limitations of organ transplants (supply and source) |
|
|
what are the two types of stem cells?
|
adult and embryonic
|
|
|
stem cells: inner cell mass cells continue to proliferate ___ in culture
|
indefinitely
|
|
|
Basic science problems to overcome with stem cells (3)
|
1)how to direct differentiation of cells down specific pathways
2)how to overcome immune rejection 3)how to make an organ |
|
|
Current understanding of the potential of stem cells: (7)
|
1)bone marrow
2)pancreatic islet cells for diabetes 3)heart muscle cells for heart disease 4)nerve cells for parkinson's/alzhiemer's 5)prevention/treatment of birth defects 6)toxicity testing 7)identify drug targets and test potential therapeutics |
|
|
somatic cell in stem cell research can be from...except...
|
any cell of the body (except germ/egg cell)
|
|
|
what's the general strategy for expressing insulin in bacteria (4)
|
1)separate mRNA with gene
2)use reverse transcriptase to make cDNA 3)join to plasmid: recombinant plasmid 4)infect E. Coli |
|
|
mature insulin is really made from 2 polypeptides held together by ___ bonds, which are made using ___ residues
|
disulfide
cysteine |
|
|
why do you need b-galactosidase when making insulin? What chemical do you use to cleave b-galacto and chain?
|
-cause A/B chains too small and it can bind to sugars
-Cyanogen bromide |
|
|
Normal insulin has a problem:
How did they fix it |
it aggregates
replaced non-polar amino acid (proline) with charged one (asparctic acid). |
|
|
Huntingtons usu fatal how many years after symptoms develop?
|
10-20
|
|
|
What do we use to find defective gene in huntington's. What are the two alleles
|
-Restriction Fragment Length Polymorphisms (RFLPs)(size variants of fragments)
-Each recognition site has two alleles: the site is either present or absent. |
|
|
number of ___ varies among individuals because the sequence of bases varies among individuals (we don’t all have an identical genome sequence).
|
recognition sites
|
|
|
Steps in southern blotting to visualize RFLPs (7)
|
1)cut DNA
2) load onto gel for electrophoresis 3)electrophoresis: use voltage difference to separate DNA fragments by size (smaller ones run faster) 4)treat strands to make them single-stranded 5)blotting:(alkaline solution wicks up into the blotting paper, carrying the DNA from the gel onto nylon filter where it is then permanently bound 6)hybridization with radioactive probe (incubate filter with solution containing probe which then binds to the fragments containing the complementary sequences 7)autoradiography |
|
|
Charge on DNA
|
negative (phosphorus)
|
|
|
what chromosome is the defective gene in Huntington's
|
4
|
|
|
HD gene code for huntingtin which appears to play an important role in ___. It's 5' end has a repeated sequence of ___ coding for ___
|
-in development of nerve cells
-CAG -glutamine |
|
|
Normal person have CAG repeat count of ___. If it's greater thn ___ get disease and if it's more than 100
|
7-34
40 you get severe HD (juvenile) |
|
|
___ slow down progression of Huntington's
|
omega-3 fatty acids
|
|
|
______ will vary if you have diseases so you could use ___ to help in locating and characterizing genetic diseases.
|
gene expression
microarrays |
|
|
Two types of gene therapy
|
germ-line gene therapy
somatic cell gene therapy |
|
|
transgene present in germ cells (eggs and sperm), thus alleles that are passed on to progeny are changed (not being pursued in humans for ethical reasons but would work). What type of treatment is this?
|
germ-line gene therapy
|
|
|
cure genetic defect in an affected somatic cell type
(pursued in humans but results are mixed). What treatment is this? |
2) somatic cell gene therapy
|
