Term
| Genetic change in Bacteria occurs by what 2 mechanisms? |
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Definition
| mutation and horizontal gene transfer |
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Term
| A mutant that requires a growth factor |
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Definition
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Term
| A mutant that does NOT require a growth factor |
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Definition
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Term
| genetic changes that result from normal cell processes and occur at a low rate. (Chance of mutation btwn one in 10,000 and one in a trillion) |
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Definition
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Term
| a mutation in which only one base pair is changed |
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Definition
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Term
| This mutation has a codon that still specifies for the wild-type amino acid. |
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Definition
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Term
| The typical phenotype of strains found in bacteria is called the _______ ______, and it is used to compare against other strains. |
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Definition
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Term
| This mutation results when the altered codon specifies a different amino acid. |
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Definition
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Term
| This mutation occurs when the altered codon is a stop codon. (results in shorter, sometimes non-functional protein.) |
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Definition
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Term
| Adding or subtracting one or two nucleotides causes this mutation |
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Definition
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Term
| segments of DNA that can move from one location to another in a cell's genome. |
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Definition
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Term
| What happens to the gene the transposon "jumps" into? |
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Definition
| It is inactivated or its function destroyed by insertion of the transposon. |
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Term
| Which is generally more severe, a missense mutation or a nonsense mutation? |
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Definition
| the nonsense mutation is usually worse because it generally houses a stop codon that won't even make the protein long enough. |
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Term
| genetic changes that occur due to an influence outside of the cell |
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Definition
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Term
| An agent that induces genetic change |
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Definition
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Term
| These are a type of mutagen that structurally resemble nucleobases, but have different hydrogen-binding properties. |
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Definition
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Term
| These are mutagens that are a flat molecule that can insert btwn adjacent base pairs in a strand of DNA. THis produces enough space btwn the two that errors are made during replication. |
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Definition
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Term
| What are some of the main mutagens? |
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Definition
| Ultraviolet light, x-rays(radiation), transposons, intercalcating agents, base analogs, and chemical mutagens |
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Term
| What mutagen causes thymine dimers, and why does it kill cells? |
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Definition
| Ultraviolet light causes thymine dimers and it happens because it causes covalent bonds to form btwn adjacent thymine molecules so that they cannot fit properly into the double helix. |
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Term
| This enzyme proofreads not only synthesizes DNA, but also proofreads it. It can back up and excise a nucleotide not correctly hydrogen bonded to the opposing nucleobase. |
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Definition
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Term
| This fixes errors missed by the proofreading of DNA polymerase |
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Definition
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Term
| what allows for mismatch repair to distinguish btwn the template strand and the new strand? |
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Definition
| The new strand is not yet methylated, whereas the template is. |
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Term
| This mechanism is found only in prokaryotes and needs light in order to work. |
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Definition
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Term
| In this type of DNA repair, an enzyme uses the energy of visible light to break the covalent bonds of the thymine dimer. |
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Definition
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Term
| In this repair process, an enzyme makes single-stranded cuts that flank both sides of the damaged region to remove the strand. |
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Definition
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Term
| This repair mechanism is a last-ditch effort to repair DNA. It is used when DNA is heavily damaged by UV light that no other repair mechanism can fix. DNA and RNA polymerases are stalled so cells cannot replicate, while a type of DNA polymerase synthesizes new regions of DNA.(no proofreading) |
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Definition
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Term
| in regards to mutant selection, in this method, cells are inoculated onto an agar medium that supports only the mutant. |
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Definition
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Term
| This method of selection is used to isolate an auxotroph from a prototrophic parent strain. |
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Definition
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Term
| This is a method for indirect selection of auxotrophic mutants. velvet is used to make replicas of a colony in a nutrient agar and one with glucose-salts agar. |
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Definition
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Term
| This is used to increase the amount of auxotrophs in a broth culture. It is helpful because mutations are still low. The use of penicillin kills the actively growing prototrophic cells in a glucose-salts medium, but allows the auxotrophs to survive. Then the penicillin is killed by penicillinase. |
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Definition
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Term
| a chemically defined broth medium with no added growth factors. |
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Definition
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Term
| This test uses direct selection to determine the effect of a test chemical on the reversion rate of a histidine-requiring auxotroph of salmonella. |
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Definition
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Term
| DNA that has an origin of replication |
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Definition
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