Genetic mutations can cause a variety of diseases. Genetic mutations are changes in the DNA sequence that make up the genetic code. These changes can be inherited or acquired during a person’s lifetime. Some genetic mutations cause no symptoms or only mild symptoms, while others result in life-threatening diseases such as cancer or neurodegenerative disorders like Alzheimer’s disease.
The most common way for genetic mutations to occur is when errors occur during DNA replication (the process by which cells make copies of their DNA). These errors are usually caused by environmental factors such as exposure to certain chemicals or radiation (like X-rays) or by mistakes made by enzymes in the cell that help with replication.
Other types of mutations include those caused by:
Chemical/physical damage to DNA — including ultraviolet light; ionizing radiation; mutagenic chemicals like benzene, formaldehyde and ethylene oxide; and toxins like arsenic, lead, cadmium and mercury
Spontaneous chemical changes — called deamination — where nitrogen bases in DNA are converted into other substances by enzymes in our cells
Insertion/deletion mutations — where extra nucleotides are added or deleted from the DNA strand
The following are different types of mutations:
Mutations in a single gene. These can be dominant or recessive, and they can cause a variety of diseases, including hemophilia, sickle cell anemia, Tay-Sachs disease and cystic fibrosis.
Mutations in multiple genes. These can lead to complex diseases like cancer, diabetes and heart disease.
A change in the number of chromosomes (aneuploidy). Some aneuploidies are lethal; others lead to miscarriages or birth defects like Down syndrome.
A change in the structure of chromosomes (deletion or duplication). These changes can be harmful or harmless depending on where they occur on the chromosome.
In this pogil, you will be given a scenario and asked to identify the type of mutation that caused it. You can also use this as a diagnostic tool to help with your understanding of genetic mutations.
Scenario: A man has two children, a son and a daughter. They both have recessive traits (blue eyes, brown hair). However, when he has his third child with another woman, the child has dominant traits (green eyes, blond hair).
a) What type of mutation could have caused this?
b) How do you know?
Genetic mutations are changes to DNA that can be passed on to future generations. This is a pogil activity for grades 9-12, but could also be used in lower grades with modifications.
In this pogil activity, students will experiment with the effects of genetic mutations on bacteria. The goal is to understand the effects of mutations and how they can be used to develop new drugs or other products.
To begin, students will need a plate of E. coli bacteria growing on agar plates (you can use this kit). You will also need one fluorescein dye solution (dissolved in water), one tetracycline solution (dissolved in water), and one antibiotic control solution (dissolved in water).
Students will work in groups of 2-3, each group using a different antibiotic control solution. They should prepare samples by adding 1 ml of each solution to 0.5 ml of bacteria culture growing on an agar plate. After mixing well, they should spread a thin layer of the mixture across the surface of an agar plate using a toothpick or clean stick (to avoid contaminating other plates).
The plates should sit at room temperature overnight so that the bacteria can grow and mutate into new strains before
