Table of contents

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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

3. Extensions to Mendelian Inheritance

Overview of interacting Genes

Genetics

3. Extensions to Mendelian Inheritance

Overview of interacting Genes

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Multiple Choice

When the phenotypic values for a polygenic trait are plotted on a graph, the distribution is:

bimodal

skewed to the right

uniform

approximately normal (bell-shaped)

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Verified step by step guidance

Understand that polygenic traits are controlled by multiple genes, each contributing a small effect to the overall phenotype.

Recognize that when many genes influence a trait, the combined effect tends to produce a continuous range of phenotypes rather than discrete categories.

Recall the Central Limit Theorem, which states that the sum of many independent random variables tends to follow a normal distribution, regardless of the individual distributions.

Apply this concept to polygenic traits: the phenotypic values, being the sum of many genetic effects plus environmental influences, will approximate a normal (bell-shaped) distribution when plotted.

Therefore, the graph of phenotypic values for a polygenic trait typically shows a bell-shaped curve, indicating a normal distribution rather than bimodal, skewed, or uniform.