Entry Exam Category: High School Equivalency Exams
Course: General Education Development (GED)
Exam: GED Science and Practice Test
Practice Question
Extract
Mr. Scott has been diagnosed with hemochromatosis. He reads the following information on medical websites. Hereditary hemochromatosis is a genetic disease that alters the body's ability to regulate iron absorption. Common symptoms include tiredness, joint pain, abdominal pain, skin darkening, hair loss, and weakness.
Hereditary hemochromatosis is usually caused by a common gene mutation known as C282Y. But other mutations that cause this disease have also been Identified, including one known as H63D.
A child who inherits two copies of a mutated gene (one from each parent) is highly likely to develop the disease. However, not all people who have two mutated copies develop signs and symptoms of hereditary hemochromatosis.
People who inherit only one copy of the mutated gene are carriers, but usually have no symptoms, or have very mild symptoms since one correct copy of the gene appears to adequately regulate iron absorption.
Hereditary hemochromatosis is usually caused by a common gene mutation known as C282Y. But other mutations that cause this disease have also been Identified, including one known as H63D.
A child who inherits two copies of a mutated gene (one from each parent) is highly likely to develop the disease. However, not all people who have two mutated copies develop signs and symptoms of hereditary hemochromatosis.
People who inherit only one copy of the mutated gene are carriers, but usually have no symptoms, or have very mild symptoms since one correct copy of the gene appears to adequately regulate iron absorption.
Which statement correctly summarizes this information?
Answer Choices
- A: Hemochromatosis is a dominant genetic disease caused by a single mutation.
- B: Hemochromatosis is a recessive genetic disease, but is caused by a lack of iron.
- C: Hemochromatosis is a recessive genetic disease, but the expression differs in individuals.
- D: Hemochromatosis is a dominant genetic disease that can be caused by several different alleles.
Correct Answer: C
Rationale: Hemochromatosis requires two mutated genes (recessive) and expression varies among individuals.