Three independently assorting STR markers (A, B, and C) are used to assess the paternity of a colt recently born to a quarter horse mare. Blood samples are drawn from the mare, her colt, and three possible male sires (S₁, S₂, and S₃). DNA at each marker locus is amplified by PCR, and a DNA electrophoresis gel is run for each marker. Amplified DNA bands are visualized in each gel by ethidium bromide staining. Gel results are shown below for each marker. Evaluate the data and determine if any of the potential sires can be excluded. Explain the basis of exclusion, if any, in each case.
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
- 19. Cancer Genetics29m
- 20. Quantitative Genetics1h 26m
- 21. Population Genetics50m
- 22. Evolutionary Genetics29m
18. Molecular Genetic Tools
Methods for Analyzing DNA
Problem 14
Textbook Question
What advantages do cDNA libraries provide over genomic DNA libraries? Describe cloning applications where the use of a genomic library is necessary to provide information that a cDNA library cannot.

1
Understand the difference between cDNA libraries and genomic DNA libraries: cDNA libraries are derived from mRNA and represent only the expressed genes in a specific tissue or cell type, while genomic DNA libraries contain the entire genome, including both coding and non-coding regions.
Identify the advantages of cDNA libraries: Since cDNA libraries are based on mRNA, they exclude introns and non-coding regions, making them ideal for studying gene expression, producing recombinant proteins, and analyzing functional genes.
Recognize the limitations of cDNA libraries: cDNA libraries do not provide information about regulatory sequences, introns, or non-expressed genes, which are present in genomic DNA libraries.
Describe applications where genomic DNA libraries are necessary: Genomic libraries are essential for studying gene regulation, identifying promoter regions, analyzing non-coding DNA, and understanding the complete genomic structure of an organism.
Summarize the complementary roles of both libraries: While cDNA libraries are useful for functional studies and protein production, genomic DNA libraries are indispensable for understanding the full genetic architecture and regulatory mechanisms of an organism.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
cDNA Libraries
cDNA libraries are collections of complementary DNA synthesized from messenger RNA (mRNA) through the process of reverse transcription. They represent only the expressed genes in a cell at a given time, allowing researchers to study gene expression and protein coding sequences without the non-coding regions found in genomic DNA.
Recommended video:
Guided course
Methods for Analyzing DNA and RNA
Genomic DNA Libraries
Genomic DNA libraries contain fragments of an organism's entire genome, including both coding and non-coding regions. This comprehensive representation is essential for studying the complete genetic makeup, regulatory elements, and non-coding RNA genes, which are not captured in cDNA libraries.
Recommended video:
Guided course
Genomic Variation
Cloning Applications
Cloning applications often require genomic libraries when researchers need to isolate and study specific genes, regulatory sequences, or non-coding regions that are crucial for understanding gene function and regulation. For example, identifying mutations in non-coding regions or studying complex traits often necessitates the use of genomic libraries.
Recommended video:
Guided course
Positional Cloning
Watch next
Master Methods for Analyzing DNA and RNA with a bite sized video explanation from Kylia
Start learningRelated Videos
Related Practice
Textbook Question
463
views