Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

4. Genetic Mapping and Linkage

Mapping Genes

Genetics

4. Genetic Mapping and Linkage

Mapping Genes

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Multiple Choice

The genetic distances between three genes (ab, nm, kf) were determined using a two-point mapping cross. Determine the sequence of the three genes.

Ab – nm – kf

Ab – kf – nm

Kf – ab – nm

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Verified step by step guidance

Examine the genetic distances provided in the table: ab-nm is 45, ab-kf is 3, and nm-kf is 42.

Understand that the genetic distance is a measure of how far apart genes are on a chromosome, with larger numbers indicating greater distances.

To determine the sequence of genes, consider the smallest distance first, which is ab-kf (3). This suggests that ab and kf are closest to each other.

Next, consider the distance between nm and kf (42). Since nm is far from kf, nm is likely on the opposite side of kf compared to ab.

Finally, verify the sequence by checking the distance between ab and nm (45), which supports the sequence ab-kf-nm, as ab and nm are the farthest apart.

9:09m

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Open Question

Based on previous family studies, an autosomal recessive disease with alleles A and a is suspected to be linked to an RFLP marker. The RFLP marker has four alleles, R₁, R₂, R₃, and R₄. The accompanying pedigree shows a three-generation family in which the disease is present. The gel shows the RFLP alleles for each family member directly below the pedigree symbol for that person. After determining the genotypes for the RFLP and disease gene for each family member, answer the following questions.Based on your analysis, what is the recombination frequency in this family? Explain how you obtained your answer.

Open Question

Based on previous family studies, an autosomal recessive disease with alleles A and a is suspected to be linked to an RFLP marker. The RFLP marker has four alleles, R₁, R₂, R₃, and R₄. The accompanying pedigree shows a three-generation family in which the disease is present. The gel shows the RFLP alleles for each family member directly below the pedigree symbol for that person. After determining the genotypes for the RFLP and disease gene for each family member, answer the following questions.Is there any evidence of recombination in this pedigree? If so, identify the recombinant individuals and illustrate the recombination that has occurred.

Open Question

Based on previous family studies, an autosomal recessive disease with alleles A and a is suspected to be linked to an RFLP marker. The RFLP marker has four alleles, R₁, R₂, R₃, and R₄. The accompanying pedigree shows a three-generation family in which the disease is present. The gel shows the RFLP alleles for each family member directly below the pedigree symbol for that person. After determining the genotypes for the RFLP and disease gene for each family member, answer the following questions.What is the most likely arrangement of syntenic alleles for the RFLP and the disease gene in I-1 and I-2?

Open Question

For six genes known to be linked on chromosome 10 of corn (Zea mays), the recombination frequencies between various pairs have been determined in a series of genetic crosses. Use the recombination frequency data in the table below to determine the order of and distance between the genes on a genetic map. The gene lc1 is known to be closest to the telomere of the chromosome.

Multiple Choice

True or False:Recombination frequencies are never greater than 50%

Multiple Choice

Using the following data collected from a test cross, calculate the recombination frequency.

Open Question

In a diploid species of plant, the genes for plant height and fruit shape are syntenic and separated by 18 m.u. Allele D produces tall plants and is dominant to d for short plants, and allele R produces round fruit and is dominant to r for oval fruit.

Give the same information for a plant with the genotype Dr/dR.

Open Question

Genes A, B, and C are linked on a chromosome and found in the order A–B–C. Genes A and B recombine with a frequency of 8%, and genes B and C recombine at a frequency of 24%. For the cross a⁺b⁺c/abc⁺×abc/abc, predict the frequency of progeny genotypes. Assume interference is zero.

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