13. Mendelian Genetics

If a genetic counselor was examining a pedigree chart and noticed an occurrence of a disease in every generation, the counselor would most likely assume that the disease was caused by:

The pedigree chart shown depicts the inheritance pattern of __________.

Determine the likely pattern of inheritance in the following pedigree. List the genotypes of the numbered individuals in this order: #1, #2, and #3.

The following pedigree is for the ABO blood type group, which is an example of autosomal inheritance. Using the I^A, I^B, i for the alleles, fill in the top half of each box/circle with the genotype. Also, fill in the bottom half of each box/circle with the phenotype (A, B, AB, or O blood type). If it is impossible to know for certain a specific allele in the genotype, then place a '?' as a placeholder to represent the allele that is in question.

Hemochromatosis is an inherited disease caused by a recessive allele. If a woman and her husband, who are both carriers, have three children, what is the probability of each of the following? a. All three children are of normal phenotype. b. One or more of the three children have the disease. c. All three children have the disease. d. At least one child is phenotypically normal.

Karen and Steve each have a sibling with sickle-cell disease. Neither Karen nor Steve nor any of their parents have the disease, and none of them have been tested to see if they carry the sickle-cell allele. Based on this incomplete information, calculate the probability that if this couple has a child, the child will have sickle-cell disease.