Exam 5: Linkage, Recombination, and Eukaryotic Gene Mapping

A) phenotypes that are similar.
B) recombination frequencies of less than 50%.
C) homozygosity when involved in a testcross.
D) a greater number of recombinant offspring than parental offspring when involved in a testcross.
E) a lack of recombinant offspring when a heterozygous parent is testcrossed.

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A) 0) 16 with one degree of freedom
B) 0) 16 with three degrees of freedom
C) 0) 48 with one degree of freedom
D) 0) 48 with two degrees of freedom
E) 4) 56 with one degree of freedom

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The various Y chromosomes markers would ...

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A) involves on or more genes found on different chromosomes.
B) is when two genes interact with each other to form a phenotype.
C) is formed between one or more genes residing close together on a chromosome.
D) involves genetic recombination of greater than 50% among two genes.
E) is when one gene effects the expression of another gene.

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A) 27.1 and one degree of freedom
B) 14.9 and three degrees of freedom
C) 14.9 and two degrees of freedom
D) 27.1 and three degrees of freedom
E) 0) 42 and two degrees of freedom

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A) counting the number of recombinant and parental offspring when an individual who is heterozygous for two genes is testcrossed.
B) performing a chi-square test on the F₂ progeny when an individual who is homozygous for two genes is initially crossed to an individual who is homozygous recessive for these two genes.
C) counting the number of offspring who are expressing the dominant phenotype when a heterozygous individual for two genes is testcrossed.
D) performing a chi-square test of the progeny of a cross between parents who are both heterozygous for the same two genes.
E) counting the number of offspring that are found in the cross of an individual who is heterozygous for two genes with another parent who is homozygous dominant for one of these genes and homozygous recessive for the other gene.

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A) 0) 25
B) 0) 002475
C) 0) 000025
D) 0) 004975
E) 0) 495

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A) 0) 168
B) 0) 0081
C) 0) 032
D) 0) 062
E) 0) 13

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A) two genes are assorting independently.
B) two genes are far apart on a genetic map.
C) one crossover inhibits another.
D) the number recombinant progeny classes in the testcross of a heterozygote exceeds the number of parental progeny.
E) a crossover causes the termination of the meiosis event in which the crossover is occurring.

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A) with genes that are far apart, double crossover and other multiple crossover events often lead to lethal recombinants that reduce the number of recombinant progeny.
B) with genes that are far apart, double crossover and other multiple crossover events often lead to nonrecombinant or parental offspring and thus reduce the true map distance.
C) crossover interference will cause more double crossover and other multiple crossover events to occur than would be expected and thus result in a higher number of recombinant progeny than expected to occur with genes that are far apart.
D) double crossover and other multiple crossover events occur more often when genes are close to each other and can be readily detected, so these map distances are more accurate than those for genes that are far apart.
E) when genes are far apart, single crossover recombinant classes are more difficult to detect than when genes are close together.

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A) one parent who is homozygous recessive for one gene pair and a second parent who is homozygous recessive for a second gene pair.
B) one parent who is homozygous dominant for one or more genes and a second parent who is homozygous recessive for these same genes.
C) two parents who are both heterozygous for two or more genes.
D) one parent who shows the dominant phenotype for one or more genes and a second parent who is homozygous recessive for these genes.
E) one parent who shows the recessive phenotype for one or more genes and a second parent who is homozygous dominant for these genes.

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A) A b D
B) a B D
C) A D B
D) a d b
E) B a d

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A) crossing over and chromosome interference.
B) chromosome interference and independent assortment.
C) somatic-cell hybridization and chromosome interference.
D) complete linkage and chromosome interference.
E) crossing over and independent assortment.

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A) independent assortment association.
B) linkage of genetic traits to haplotypes within a population.
C) analysis of single nucleotide polymorphisms.
D) likelihood of linkage between genes on different chromosomes.
E) linkage disequilibrium among other genes.

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A) 1 cM
B) 5 cM
C) 10 cM
D) 12 cM
E) 20 cM

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A) The two genes are assorting independently in female 1 and are linked in female 2.
B) The two genes are linked in female 1 and are assorting independently in female 2.
C) The two alleles are in the coupling configuration in female 1 but in the repulsion configuration in female 2.
D) The two alleles are in the repulsion configuration in female 1 but in the coupling configuration in female 2.
E) The two genes are likely located on a sex chromosome in female 1 and are likely located on an autosome in female 2.

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A) the interference is high and one crossover suppresses the occurrence of a second one.
B) no double crossovers were found in the progeny of a testcross, even though some were expected based on probability.
C) double crossovers were found in the progeny of a testcross, but there were fewer of them than would be expected based on probability.
D) there were more double crossovers in the progeny than would be expected based on probability.
E) the genes involved were actually assorting independently.

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A) 1 cM
B) 5 cM
C) 10 cM
D) 20 cM
E) 30 cM

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