Exam 5: Genetic Linkage and Mapping in Eukaryotes

Construct a map of the chromosome, with the most accurate map distances, from the follow recombination frequencies between individual pairs of genes: C - F 13%, V - F 20%, V - C 8%, S - F 4%, C - S 9%,

What is observed when syntenic genes are close enough to one another that they are unable to assort independently?

A geneticist is mapping the chromosomes of the newly captured gremlin. Stripe is heterozy for three linked genes with alleles Ee, Hh, and Bb, that determine if gremlins are evil (E), ha (H), and biting teeth (B). In order to determine if the three genes are linked, a standard testc was done, and the 1000 offspring had the following genotypes: 48 ee Hh bb 36 eehh Bb 400 ee Hh Bb 4 Ee Hh Bb 426 Eehh bb 46 Eehh Bb 38 Ee Hh bb 2 eehh bb Diagram the alleles on the homologous chromosomes of the heterozygous individuals with correct gene order.

Genes associated by GWAS studies have all of the following characteristics except?

What type of test would you use to determine whether observed data constitute evidence of genetic linkage or are simply a case of chance variation from expected values?

A geneticist is mapping the chromosomes of the newly captured gremlin. Stripe is heterozygous for linked genes with alleles Ee, Hh, and Bb, that determine if gremlins are evil (E), have hair (H), and b teeth (B). In order to determine if the three genes are linked, a standard testcross was done, and the offspring had the following genotypes: 48 ee Hh bb 36 ee hh Bb 400 ee Hh Bb 4 Ee Hh Bb 426 Eehh bb 46 Eehh Bb 38 Ee Hh bb 2 ee hh bb What is the recombination frequency between genes E and H?

What is the term for chromosomes that do not reshuffle the alleles of linked genes?

Genetic linkage leads to the production of a significantly greater than expected number of gametes containing chromosomes with _________.

The Zmax from the analysis of a disease gene N and the DNA marker H was 2.5 at 0 = 0.1. Which of the following is the best interpretation of this result?

Recombination frequencies between genes can be altered by all the following except?

In an individual that is dihybrid for completely linked genes, which alleles would you expect in the gametes?

What organism exhibits complete genetic linkage, meaning there is no recombination between homologous chromosomes?

In fruit flies, red eyes (pr+_) are dominant to purple eyes (prpr) and normal wings (vg+_) are dominant to vestigial wings (vgvg). The genes are located on the same chromosome. A pure- breeding red- eyed fly with vestigial wings was crossed with a pure- breeding purple- eyed fly with normal wings. All of the F1 progeny had a WT phenotype. The recombination frequency between the two genes is 15%. If an F1 individual were test crossed, what percentage of the progeny would you expect to have the WT phenotype?

Assuming three genes are linked, how many recombinant genotypes would you expect and at what frequency?

After analysis of 100 pedigrees, the Zmax from the analysis of linkage between a disease gene D and the DNA marker P was found to be 3.5 at 0 = 0.25. Which of the following is the best interpretation of these results?

Alleles of linked genes usually segregate together during meiosis. When they don't, it is because__________ has occurred between them.

What is the relationship between linked genes and syntenic genes? Are syntenic genes always linked?Are linked genes always syntenic? Describe what is meant by each term.

What is the Lod score?

What unit of physical distance between genes on a chromosome provides a convenient way to relate the recombination frequencies for linked genes with their positions and order along a chromosome?

Two genes, A and X, exhibit incomplete linkage. The frequency of each parental gamete (AX and ax) is 45%. What is the approximate frequency of the Ax gamete?