Module 7
1. Module 7
1.2. In this Module
Module 7—Molecular Genetics: DNA, RNA, and Protein Synthesis
In this Module
Inquiry Question: Can the transmission of traits at the molecular level be explained by understanding the structure of DNA, its role in protein synthesis, and how it could mutate?
There are six lessons in Module 7.
Most of the lessons are designed to take you 80 minutes to complete; however, some lessons may take longer because of the significance of the concept being covered in the lesson. The suggested lesson times do not include the time needed to complete such activities as “Try This,” “Watch and Listen,” assignments, practice questions, review, or research.
This module corresponds to Chapter 18, pages 624 to 665, in your textbook. You may choose to briefly read through these pages for an overview before you begin this module.
Lesson 1: DNA Structure
All organisms begin life as a single cell. All of the information for forming body parts and for controlling body processes must be stored in that single original cell. Many scientists, and various events and discoveries, led to the identification of the molecule that holds all of this cellular information, DNA.
In this lesson you will consider the following focusing questions:
- What is the history of the discovery of DNA?
- What is the structure of DNA?
- What is the significance of finding the DNA code?
Lesson 2: DNA Replication
If you had the complete Book of Life, how would you copy it for your children? Would you write it out? Would you photocopy it? How would you know that it didn’t contain any mistakes? The DNA from the single original cell must be replicated as the cell divides. Mistakes in this replication process can be life-threatening.
In this lesson you will consider the following focusing questions:
- How does DNA code our genetic message?
- How do new cells get a copy of this message?
Lesson 3: Protein Synthesis
Do you have milk “issues”? Many people are not able to eat or drink dairy products because they contain lactose. One reason for this intolerance is their body’s inability to make the enzyme lactase. Our bodies use the DNA in our cells to build all of the proteins needed to survive, including enzymes like lactase. This process is called protein synthesis.
In this lesson you will consider the following focusing question:
- How is the genetic code in DNA copied and used to assemble amino acids into proteins?
Lesson 4: Changes in the Genetic Code
Do genetic superheroes really exist? It depends on your definition of “superhero.” On the African subcontinent, communities are ravaged by malaria. The genetic makeup of those communities is changing. In related communities without malaria, founded by the African communities, the genetic makeup is not changing. In Africa, the gene for sickle cell anemia is increasing in frequency in the population’s gene pool. People with one copy of the sickle cell gene can survive malaria. These individuals are stronger, live longer, and pass the gene to their children. In this lesson, we will explore how random changes (mutation) can provide a source of genetic variation in a population.
In this lesson you will consider the following focusing questions:
- What kinds of changes in DNA can result in variation?
- How can mutations in DNA have both a positive and a negative result?
- What are the causes of changes in DNA?
Lesson 5: Genetic Engineering
Who owns your DNA? Will you always own your DNA? The Human Genome Project has now identified the entire sequence of human DNA. How will this important knowledge be used? Research companies have valuable patents on specific sequences of plant and animal DNA sequences developed in laboratories. Will they also patent human DNA sequences? This valuable knowledge of DNA sequences has been used to transform DNA through genetic engineering.
In this lesson you will consider the following focusing questions:
- What roles do restriction enzymes and ligases play in changing the genome?
- What are some technologies involved in genetic engineering?
- What are the implications of genetic manipulation?
Lesson 6: You Are Your Genetic Code
Human DNA is similar to the DNA of a pig and to a stalk of corn. How did we get to be similar? What does this mean? In this lesson we will see how DNA can be used to trace evolutionary and genetic relationships among organisms and species.
In this lesson you will consider the following focusing question:
- How can base sequences be used to trace relationships between organisms within a family and between different species?