Biology: A Guide to the Natural World

Chapter 12: Chromosomes and Inheritance

Post-quiz: Some Human Genetic Disorders

1. How many pairs of autosomes are present in humans? [Hint]

2. The condition found mostly in plants, where there are more than 2 sets of chromosomes per cell is called: [Hint]

3. Phenylketonuria is caused by an autosomal recessive allele. A man is the carrier of the disorder; his wife does not have PKU and is not a carrier. What is the probability their offspring will have the disorder and other will be carriers? [Hint]

4. A karyotype reveals that a woman is carrying a fetus that has 47 chromosomes. The test reveals that the genotype of the fetus is XYY. Which of the following statements would be correct? [Hint]

5. Which of the following explanations could account for the fact that dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders? [Hint]

6. If a disease is caused by a dominant allele, it means that a person with the disease: [Hint]

7. A person with an inherited disorder has a child with a person who does not have the disorder. Half the children have the disorder, both males and females. The pattern of inheritance is: [Hint]

8. A karyotype you are viewing shows an extra piece of chromosome #1 attached to chromosome #22. What type of abnormality caused this? [Hint]

Answer choices in this exercise are randomized and will appear in a different order each time the page is loaded.

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