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About the Course Module

Tour of the Genome

Enter the Course Module: 

This module describes genome structure and how it relates to function. It uses videos to introduce and visually represent the human genome. In small groups, students investigate how problems with genome structure can result in genetic diseases.

Estimated Module Timing: 

*Genome Overview—intro video, discussion, and questions: 25 minutes

*Chromosome Close-up—video, discussion, and questions: 20 minutes

*Packaging DNA—video, discussion, and questions: 10 minutes

*Chromosome Arrangement—video, discussion, and questions: 20 minutes

*Genome Structure and Disease—do these all together: 40–100 minutes, depending on how you have your students present their findings

Genome Overview

1. A genome is a parts list and instruction manual for life that is made of all the deoxyribose nucleic acid (DNA) in an organism.

2. Adult diabetes

3. 99.9% identical between individual humans, 85% identical between humans and mice

 

Chromosome Close-up

1. Exons carry the DNA code for proteins, while the introns are noncoding.

2. Hemogloblin (note that beta globin, delta globin, beta globin pseudogene, gamma globin, and epsilon globin make up hemoglobin)

 

Packaging DNA

1. a) DNA wraps around histones (protein molecules) = nucleosome, b) nucleosomes packaged in a thread = chromatin, c) coiled chromatin (“solenoid”) can loop/coil into chromosomes

2. Chromosomes are present in the nucleus only during cell division.

 

Additional Resources

DNA replication during mitosis

DNA replication during meiosis

 

Chromosome Arrangement

1. “Bowl of Spaghetti” model

2. “Chromosome Territory” model because a laser damaged only a few chromosomes in each nucleus. The researchers could tell which chromosomes were damaged because the DNA repaired itself using special radioactively labeled nucleotides, which were distinct from the original nucleotides in the chromosomes.

 

Karyotyping

Additional Resources

Balanced translocation

Unbalanced translocation

 

Activity

The links with resources on the seven genetic disorders will provide the information to answer the questions.

a) Which chromosome(s) are modified in this disorder? Give a brief description of how the genome of individuals with this disorder is different from the genomes of people who do not have this disorder.

b) What are the phenotypes (observable traits) of this disorder?

Responses for each disorder can be found here.

 

Additional Resources

Overview of common genetic disorders

Karyotypes of the above disorders (scroll to the bottom of the page)