When the cystic fibrosis gene was discovered in 1989,only one mutation was described,and a diagnostic test was developed to detect it.Over the years,as more mutations were discovered,they were added to the test panel.Today,most pregnant women are offered a CF test that detects 100 or so alleles,although more than 1600 mutations have been discovered.Which of these is reflected by the given facts?
A)The presence of multiple alleles
B)The presence of pleiotropy
C)The presence of phenocopy
D)The presence of lethal alleles

Question

Quizplus · Accepted Answer

The fact that more than 1600 mutations have been discovered but only a smaller subset of 100 or so alleles are detected in the standard CF test indicates the presence of multiple alleles. Pleiotropy refers to a single gene affecting multiple traits, phenocopy refers to an environmental factor mimicking genetic expression, and lethal alleles are those causing premature death, none of which are indicated by the given facts.

When the Cystic Fibrosis Gene Was Discovered in 1989,only One