Term
When genes are close together, there is a great deal of __________ and __________ __________ are rare.
As a result, map distances are quite __________ over (long/short) distances. |
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Definition
1) Interference
2) Double crossovers
3) Additive
4) Short |
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Term
| Interference (increases/decreases) over longer __________ __________ distances and as a result, become less __________. |
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Definition
1) Decreases
2) Genetic map
3) Additive |
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Term
| What are mapping functions? |
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Definition
| 1) Mathematical equations that try to correctly predict the decrease in interference so that the reduction in observed map distances due to double crossovers is corrected and actual genetic distances can be predicted from the observed map distances. |
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Term
| Mapping functions are mathematical equations that try to correctly predict the decrease in __________ so that the reduction in observed map distances due to __________ __________ is corrected and actual __________ __________ can be predicted from observed map distances. |
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Definition
1) Interference
2) Double crossovers
3) Genetic distances |
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Term
| How are map distances measured? |
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Definition
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Term
| Map distances are related to the actual physical distance between __________ genes. |
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Definition
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Term
| Physical distance is measured in the number of __________ between __________ genes. |
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Definition
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Term
| Parts of a chromosome were more __________ occurs per unit of DNA would be (expanded/condensed)on the genetic map and where few __________ occur would be (expanded/condensed). |
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Definition
1) Recombinations
2) Expanded
3) Recombinations
4) Condensed |
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Term
| Certain sequences (usually located near the __________ and near the chromosome ends) have a compact structure in interphase (named __________). Such sequences show low recombination frequencies. |
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Definition
1) Centromeres
2) Heterochromatin |
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Term
| True or False: Females show more recombination than males in humans and there is no recombination in male Drosphila. |
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Definition
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Term
| On the average, __________ recombination occurs for every million base pairs. |
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Definition
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Term
| Why is the mapping of linked genes in human an extremely difficult task? |
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Definition
1) Experimental matings of pre-determined parental genotypes cannot be done
2) Progeny from any one mating are few
3) The parental arrangement of the 2 alleles (coupling or repulsion) cannot usually be determined
4) Often a gene does not have 100% penetrance (is not expressed all the time) |
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Term
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Definition
| 1) Log of odds defined as log(10) of the likelihood ratio |
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Term
| Generally, a lod value of __________ is an indicator of linkage and a lod value of __________ indicates independent assortment. Lod values between __________ and __________ are uninformative. |
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Definition
1) x > 3.0
2) x < -2.0
3) -2 and +3 |
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Term
| __________ crossing-over makes genes distal to the point of crossover -> __________ (on one side of centromere only) |
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Definition
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Term
| When does mitotic crossing over occur? |
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Definition
| 1) At the 4-strand stage (during prophase of mitosis) |
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