Use the Following Pedigree (Figure 14

question 57

Multiple Choice

Use the following pedigree (Figure 14.3) for a family in which dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis.

Figure 14.3
-In each generation of this family after generation I, the age at diagnosis is significantly lower than would be found in nonfamilial (sporadic) cases of this cancer (~ 63 years) . What is the most likely reason?

• A) Members of this family know to be checked for colon cancer early in life.
• B) Hereditary (or familial) cases of this cancer typically occur at earlier ages than do nonfamilial forms.
• C) This is pure chance; it would not be expected if you were to look at a different family.
• D) This cancer requires mutations in more than this one gene.
• E) Affected members of this family are born with colon cancer, and it can be detected whenever they are first tested.

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Definitions:

Ruthenium

A rare transition metal belonging to the platinum group of the periodic table, with the symbol Ru and atomic number 44.

Elemental Symbol

A one- or two-letter notation derived from the name of an element, used to represent it in chemical formulas and equations.

Rubidium

A soft, silvery-white metallic element, symbol Rb, used in research and in manufacturing specialty glasses.

Elemental Symbol

A one or two-letter abbreviation that represents an element on the periodic table.