Term
What major genetic discovery was made in 1860? |
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Definition
Mendel outlined the segregation of traits |
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Term
What major genetic discovery was made in 1869? |
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Definition
Miescher discovered a weak acid within the nuclei of white blood cells (this acid is now known as DNA) |
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Term
What major genetic discovery happened in 1870? |
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Definition
The fusion of nuclei within gametes was observed |
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Term
What major genetic discovery occured in 1882? |
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Definition
Fleming described chromosomes and chromosomal segregation (which was later found to be mitosis and meiosis) |
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Term
What genetic advancement was more widely accepted in the early 1900's? |
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Definition
Chromosomes were viewed as likely gene carriers |
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Term
Why was protein originally thought to be the carrier of heredity and not DNA? |
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Definition
Protein was very diverse and present in chromosomes whereas DNA was also found in chromosomes but it wasn't as diverse as the proteins. |
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Term
What did Griffith's experiment show? |
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Definition
Griffith's experiment showed that something within dead S cells transformed living R cells into living S cells which went on to kill the mouse subject into which both types of cells had been injected |
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Term
What critical piece of information did Avery, McLeod and McCarty discover? |
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Definition
They discovered that by adding DNAase into the transformation process shown by Griffith that no S cells would be produced after mixing heat-killed S cells and living R cells |
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Term
What crucial component of DNA did the Hershey-Chase experiment show? |
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Definition
The experiment proved that a phosphorus backbone is used to link the sugars in DNA, not a sulfur-based backbone as some thought |
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Term
What bases are used in DNA and which bases pair with which other ones? |
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Definition
There are 4 bases: adenine (A), thymine (T), Cytosine (C) and guanine (G). A and T go together and C and G go together. Any other combinations are incompatibile and will not bond correctly |
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Term
In what "direction" is the DNA read when it's made into RNA by various enzymes and what is the primary differemce in this regard between strands that face each other? |
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Definition
DNA is read from the 5' end (with phosphate) to the 3' end (with -OH). If one strand appears to be going from the 5' end to the 3' end the other strand will be read in the opposite direction even though the bases match up heading in the same direction for each strand |
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Term
How does DNA replicate and form new DNA strands? |
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Definition
One strand splits from the other and a mirroring strand is formed from free-floating DNA components in the nucleus. Each parent strand therefore becomes paired with a daughter strand |
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Term
An error in copying the DNA could lead to what? |
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Definition
A mutation in the genetic code. Just how serious this mutation is depends on the placement of the mutation |
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Term
What aspects of cells do proteins control? |
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Definition
Proteins control the physical, chemical and mechanical properties of cells. Proteins form the escence of cells and differentiate various forms of cells |
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Term
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Definition
Enzymes are important biological catalysts within various functions. Without enzymes much of the modern forms of life would not exist |
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Term
What important discovery did Archibald Garrod make in 1908? |
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Definition
He discovered that a defective enzyme was passed down through biological generations |
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Term
What were nutritional tests able to conclude in regards to mutant spore forms? |
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Definition
Mutant spores could survive in complete media but not in minimal media (which contained the absolute basic nutrients). Since regular spores could survive in minimal media those that couldn't were tagged as mutant and kept for further investigation |
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Term
After it has been determined that a mutant spore type can't grow in minimal media what are the 3 types of additives that are now tested? |
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Definition
Vitamins, amino acids and nucleic acid precursors. If any of these combinations produces growth results you procede with another round of testing for that specific group that gave positive results |
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Term
Let's say you were testing a mutagenic spore and you found it needed amino acids to grow. How could you test further? |
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Definition
Test each of the specific amino acids and see in which one of those it grows. If it grows in any of those you know that it needs that specific amino acid to grow |
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Term
Let's say you found that a mutagenic spore grows in arginine. What could you do to further test where the mutation occurs? |
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Definition
Test various precursors for arginine (or any sort of pre/postcursor for the amino acid that tested positive). From this information you can determine exactly where there is a genetic defect. |
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Term
Let's say you have substance 1 (precursor 1), substance 2 (precursor 2) and substance 3 (an amino acid). S1 is made into S2 with the help of enzyme A and S2 is made into S3 with the help of enzyme B. If enzyme A is defective, explain the effects this has on each of the substances. |
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Definition
S1 will be in excess because of the buildup of it since some will attempt to react with enzyme A but this process won't go through but the negative feedback system will assume all attempts at processing have gone through. There will be no S2 nor S3 because of this defect. |
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Term
What is the central dogma of genetics? |
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Definition
DNA is transcribed into RNA which is then translated into proteins |
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Term
What are the two major differences found in RNA which differ from the properties of DNA? |
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Definition
The base Uracil is used instead of Thymine and a ribose sugar is used instead of a deoxyribose |
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Term
In which direction is DNA "read" and how does this change? |
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Definition
DNA is read in the 5'-3' direction. The first strand of DNA (the one that gets made into proteins) goes from 5'-3' but its complimentary strand runs the opposite way when it is read (in the same 3D space as the 5'-3' primary strand the complimentary strand is 3'-5'). The resulting mRNA from the primary DNA strand is also 5'-3' |
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Term
How does tRNA differ from mRNA? |
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Definition
It contains anticodons which are opposite of those found on mRNA. They help to identify the codons that they go to in the event of a mutation or mistake in copying DNA |
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Term
What are the special codons and what do they code for? |
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Definition
AUG within mRNA stands for "Start/Methionine" and UAA, UAG and UGA stand for "Stop" |
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Term
What does a mutation refer to? |
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Definition
A mutation refers to any sort of inheritable change within a gene |
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Term
What is a synonymous replacement mutation? |
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Definition
This refers to any mutation where the mutation does not change the produced protein (this could also happen within the area of genetic material that does not code for anything) |
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Term
What is meant by a non-synonymous mutation? |
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Definition
The resulting protein is affected and is not the same |
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Term
What is meant by pheiotrphy? |
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Definition
It means that one gene can code for multiple proteins. Since a coding sequence can encounter a second start before encounter a stop multiple proteins can be created which partially share the same amino acids |
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Term
What does the term "genome" mean? |
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Definition
It means all nuclear DNA contained within a cell |
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Term
What does "proteome" mean? |
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Definition
It refers to all of the produced proteins from a cell's genetic content |
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Term
What is meant by "paralogs"? |
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Definition
Paralogs are genes/proteins which originated from the same ancestor via gene differentiation |
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Term
What is meant by "orthologs"? |
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Definition
Orthologs are genes/proteins which are genes that are related by speciation, not necessarily a common ancestor |
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Term
Before Mendel came along how were traits thought to be replicated in offspring? |
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Definition
Offspring were thought to blend the traits of their parents. An example of this sort of modern stereotype can be found in the South Park episode "Goobacks" in which everyone from the future looks and talks exactly the same as one another due to the universal blending of cultures |
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Term
What era-radical idea did Mendel propose? |
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Definition
Mendel proposed that both parents contribute very distinct traits. He proposed this idea after he analysed the ratios at which offspring were produced |
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Term
What is the advantage in using green peas in genetic experiments and what is its scientific name? |
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Definition
Green peas have many observable traits and they also self-fertilize. Its scientific name is Pisum Sativum |
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Term
What is meant by true-breeding individuals? |
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Definition
True-breeding individuals are individuals who, when self-fertilized, produce offspring exactly like themselves |
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Term
What is meant by a reciporical cross? |
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Definition
It means any sort of cross between 2 individuals of differing phenotypes |
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Term
The dominany trait means what, exactly? |
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Definition
The dominant trait is the trait that is expressed in hybrids. This only applies for cases of complete dominance |
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Term
What is the exact definition of recessive traits? |
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Definition
Recessive traits are traits that are masked within hybrids in the case of complete dominance |
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Term
What would a diheterozygous cross result in? |
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Definition
It would result in a 1-2-1 ratio of XX, Xx and xx |
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Term
What is so special about gametes? |
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Definition
The reproductive cells only have one copy of each respective chromosome so that there is not an overflow of DNA within the cell |
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Term
What is the principle of segregation? |
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Definition
It states that there's a 50% chance of a copy of each chromosome being in a gamete |
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Term
What is the definition of an allele? |
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Definition
Alleles are different versions of the same gene. These are caused by mutation and may or may not cause a negative effect within the organism |
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Term
What is the primary difference between classical and modern genetics? |
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Definition
Unlike classic genetics which focused on physical traits modern genetics looks at both physical and molecular traits |
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Term
What would happen on a gel electrophoresis for a single trait for both homo's and a het? |
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Definition
The homo dom would move the least, the het would have 2 lines, one at the level of the homo dom and one at the homo rec level and the homo rec would move farthest away from the source of the DNA |
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Term
Let's say your genetics lab TA instructs you to perform a test cross between certain individuals of a given species. How would you procede? |
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Definition
You would pair a dominant phenotype (the exact genotype of which is unknown) with a recessive phenotype (whose genotype is exactly known) |
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Term
What ratio does a 2 trait, non-overlapping cross result in? |
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Definition
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Term
What is the formula for addition rule? |
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Definition
Prob (A or B) = Prob A + Prob B. For example, for a single trait cross where the P generation are both heterozygous, to find out the rate of theoretical heterozygous offspring you take the probability of each heterozygous spot and add them together like so: 1/4 + 1/4 = 1/2 |
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Term
What is the formula for multiplication rule? |
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Definition
Prob (A and B) = Prob A x Prob B. For example, if you wanted to find the chances of getting a homozygous dominant offspring from heterozygous parents you would multiple the chance of getting the dominant allele from each parent which would be 1/2. The result would be Prob WW = ProbW from het parent A x ProbW from het parent B = 1/2 x 1/2 = 1/4 |
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