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53 Cards in this Set
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How many copies of each chromosome does a human have? What does ‘homologous chromosome’ mean? How does this relate to “2N”? |
Humans have two copies of each chromosome. Homologous chromosome means one maternal and one paternal. 2N refers to the total number of chromosomes which is two times the number of pairs |
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Is DNA charged? If so, is it negatively or positively charged? |
Yes, DNA is negatively charged due to its phosphate groups |
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How does Gel Electrophoresis work? Why does the size of the DNA fragment matter? |
The DNA is pulled toward the positive charge core. The larger the DNA fragment the further it is pulled since the charge is bigger |
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What does each “band” in the gel represent? |
A band represents DNA of a particular size |
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What is DNA Fingerprinting? How does it work? How do you interpret a DNA fingerprint? What are real world applications? |
Different Alleles move in the electrophoresis to create unique patterns that relate to DNA. Can be used in crime scene and other DNA comparing. |
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What are the two ‘critical’ enzymes used in making recombinant DNA? What is the purpose of DNA ligase? How does a restriction enzyme work? |
Two cricitical enzymes are Restriction enzyme and DNA ligase. The restriction enzyme spilts the DNA and the ligase pairs the split pieces |
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Do epigenetic changes, such as DNA methylation, alter your DNA sequence? What are (functional) consequences of epigenetic modifications to the genome? |
Chemical groups attach to DNA or to proteins around which the DNA is wrapped. DNA is silenced(not expresse, transcribed or translated). But do not change DNA itself |
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Does a gene only have a single function? How do we have such a variety of cells in our body if all of our cell contain the same general DNA? How does this relate to “gene expression”? |
A gene does not have a single function, but rather just express the info for producing proteins. This process of DNA producing the proteins is gene expression |
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How does gene therapy work? What is the role of viral vectors in this type of therapy? Why are viruses used? What types of diseases can gene therapy possibly cure? |
Gene therapy finds a non-functional gene and silences it. Viruses can latch onto chromosomes to silence them. Could cure Cancer, AIDS, Parkinson's, Alzheimer's |
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What are the possible complications of gene therapy and what causes them? (I.e. the vector, the genes, the immune system...?) |
A mistake with the vector can cause death, as it happened early in the process |
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Are there currently any gene therapy products for sale that have been FDA approved? |
Gene therapy is currently only under testing under the FDA?*** |
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How does regenerative medicine work? Why do we need the “scaffolding” for cells? What does it mean when we say the scaffolding is “seeded” with new cells? What are the two types of cells that can be used for “seeding”? (Keep in mind that they need to be able to divide to produce several types of differentiated cells.) |
This process takes organs of deceased animals and strips it down to the scaffolding(tissue), then combined with human DNA and new rat organ to rebuild original organ |
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What are stem cells? What do they do in the body? What can they be used for in medicine and research? Consider these questions for the different types of stem cells. |
Cells that can self-renew for a lifetime. They can develop or repair tissue, which could be used to fight disease |
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What are the three different stem cell fates when stem cells divide? |
1. Asymmetric Self Renewal 2. Symmetric Self Renewal 3. Symmetric Differentiation |
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What are the characteristics of adult stem cells? Embryonic stem cells? Induced pluripotent stem cells? |
Adult stem cells can copy themselves and produce functional cells. Embryonic Stem cells can develop into functional cells with purposes. Pluripotent has the potential to be both |
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How are these three types of stem cells derived (‘made’) by researchers? For example, when are human embryonic cells taken? (How many days or weeks?) What are they taken from? |
The cells are taken from the pre-implantation stage, In the 5-9 week period of gestation period of fetus |
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Can a pregnancy test detect the formation of a blastocyst in a woman? |
No, the blastocyst secretes cells detected in the pregnancy test. |
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What is the purpose/function of embryonic stem cells in the body? Of adult stem cells? |
They have the potential to develop into many useful cells in the body in it's early life |
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Why is it important to have patient-specific stem cells for stem cell treatments? |
Cells are not rejected by the body's immune system. |
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Why does the “micro-environment” matter for a stem cell? |
It regulates the function that the stem cell develops. |
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What was the significance of Thomson’s 1998 paper? What was the patent issue that we discussed in this context? |
Thomsons paper led to the patent of stem cells and DNA code, which still stands today. |
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How does antibiotic resistance occur? In other words, what were the four steps described in class for the evolution of antibiotic resistance in M. tuberculosis? |
1. A chance mutation occurs 2. Drug therapy kills non mutated cells 3. Mutant cells proliferate 4. Drug Therapy ineffective |
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What is evolution? |
A change in the relative frequency of alleles in a population |
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Do organisms evolve or do populations evolve? Why? |
populations because the organisms may be spread out over different environments |
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What are the mechanisms that can cause evolutionary change? |
Mutation, Gene Flow, Natural Selection, Genetic Drift |
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Does the rate of mutations differ among species? Are mutation always “beneficial”? |
Mutations differ among different species, and sometimes genetic mutations can be harmful |
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Is mutation alone enough to significantly change the frequency of alleles in a population? |
No, not significant enough |
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What is the main way new genetic variation arises in a population? |
Mutation |
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Does gene flow increase or decrease homogenization among populations? |
It can do both since it can bring in new alleles and take others away |
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What is an allele that has gone to fixation in a population? Explain (contrast it with the loss of an allele). |
If an allele is fixated in a population, that means it is the only one of that allele in that population, and is therefore dominant |
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Why does phenotypic variation have to be “heritable” to evolve? Why isn’t the “optimal” phenotype the only phenotype in a population? |
Mutations can cause some variations, but it has to be able to be transferred by reproduction to become heritable |
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Can populations evolve without natural selection? If so, how? |
It can change by mutation, gene flow,genetic drift and natural selection |
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What is “fitness”? How does natural selection relate to fitness? |
Fitness is an organisms strength against it's environment. Only the strong survive |
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What is natural selection? What “factors” exert selection? |
Natural selection is the process of evolution due to the survival because of a few factors. These could be: predators, food, temperature, rainfall, shelter, mates |
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What are the four necessary components for evolution by natural selection? |
A. trait is variable B. This variation is heritable. C. Individual differences exist in reproductive success (& survival). D. Differences in reproductive success are due to differences in the expression of the trait. |
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How does the example of evolution in Darwin’s finches illustrate evolution by natural selection? Make sure to talk about variation, heritability, natural selection, and fitness. |
Certain finches survived better than other because of their ability to adapt to their environment, diet, predators, and mates |
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What is ‘genetic drift’? Why does genetic drift have a stronger effect in smaller (vs. larger) populations? |
One allele becomes dominant by chance, more popular in smaller populations because it becomes easier to take over |
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What is a genetic bottleneck and what is its effect on (genetic variation in) natural population? Think about the cheetah example. |
When a population experiences a disaster that kills many of them, they are left with a lack of genetic diversity. |
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What were Darwin and Wallace’s contributions to biology? What is meant with ‘typological thinking’ and how does this contrast with evolutionary thinking, e.g. advocated by Lamarck? |
Darwin and Wallace published the ideas of evolution by natural selection and variation is important and necesary |
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How are species defined based on the biological species concept? Are there other species concepts? |
A group of organisms that can breed together.The other two are morphological(dead) and phylogenetic(common ancestor) |
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How do populations of one species become so different that they are considered different species? What must occur in order for speciation to happen (in relation to reproductive isolation and gene flow)? |
The species must be separated into separate environments, then repopulate and speciate , no gene flow, then they cannot reproduce |
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What are examples of speciation? |
Darwin's Finches |
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Are horses and donkeys considered separate species although they can reproduce to create mules? Are different dog breeds still considered the same species? (think about large size differences and how this could prevent reproduction) |
Yes they still are because they cannot produce fertile offspring. Dogs face some physical barriers but are the same species |
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Explain the process of allopatric speciation. |
When a population is separated and when they rejoin, they can no longer produce |
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What is *required* for speciation? What is required for allopatric speciation?
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Specialization requires genetic isolation that would force the species to become unable to reproduce. Allopatric requires a geographical reason for it |
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When thinking about the history of the earth as a clock, since what time has life been present on earth? How long ago did Earth originate? Life on Earth?
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Prokaryotes began over 3 and a half billion years ago, and the earth began over 4 and a half billion years |
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What are the Domains of life? Which are prokaryotes? Eukaryotes?
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Archaea , Bacteria, and Eukarya. Prokaryotes are cells without nuclei or cell membranes with simple strands of DNA, first form of life. Eventual Eukaryotas developed, more complicated and more organelles. |
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How was the earth different when life first formed on earth? (think about the gases in the atmosphere (oxygen?), temperature, UV & sunlight intensity, meteorites, volcanic activity etc.)
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There was no Oxygen, lightning and UV sun rays were much more common because the lack of atmosphere |
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What is the “four stage hypothesis” trying to explain? What are the four stages?
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Explains how life on Earth was created 1.Abiotic synthesis of organic monomers 2. Abiotic synthesis of organic polymers 3. Formation of pre-cells 4. Origin of self-replicating molecules |
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Why are membranes important?
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Can protect cell, control what goes in and out of cell |
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Was O2 present in the atmosphere when life formed? Is it beneficial to have O2 in the atmosphere and why? How did the atmosphere become oxygenated?
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Oxygen was not present but it was created by photosynthesis of organisms in the atmosphere |
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Why are fossils so important? How does fossilization work and why are fossils rare?
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Fossil provide direct evidence of past species and genetics. Fossilization works if there is slow decomposition with a rapid burial, and it must have decomposition resistant parts(bones) |
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What is a tetrapod? How is it different from a fish? Why is a “fishapod” (tiktaalik) so important (i.e. think about this fossil as a transitional form)? |
Tetrapod was a four-legged fish that lived in shallow water but could move onto land. Began transition to land, and eventually all the way to humans. |
