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 Overview

Genetics

4. Genetic Mapping and Linkage

Mapping Overview

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Multiple Choice

Which of the following steps is essential when using a three-factor cross to map the order and distances between genes on a chromosome?

Sequencing the entire genome to identify gene locations

Determining parental and recombinant phenotypes to calculate recombination frequencies between each pair of genes

Measuring the rate of DNA replication in each gene region

Observing gene expression levels in different environmental conditions

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Verified step by step guidance

Understand that a three-factor cross involves crossing organisms heterozygous for three genes to analyze the inheritance patterns of these genes together.

Identify the phenotypes of the offspring and classify them into parental (non-recombinant) and recombinant types based on the combination of traits they display.

Calculate the recombination frequencies between each pair of genes by dividing the number of recombinant offspring for that gene pair by the total number of offspring, then multiply by 100 to get a percentage.

Use the recombination frequencies to determine the relative distances between the genes on the chromosome, since recombination frequency is proportional to physical distance.

Analyze the pattern of recombination frequencies to deduce the correct order of the three genes on the chromosome, as the gene order affects the observed recombination frequencies.