Various types of mutations have been found in DNA from damaged, defective, or diseased cells. Which of the following types of mutation will manifest a phenotype only as a consequence of specific circumstances (eg, increased temperature or oxidative stress)?
A) conditional
B) dominant negative
C) gain-of-function
D) lethal
E) null

Question

Quizplus · Accepted Answer

Conditional mutations manifest a phenotype only under specific environmental conditions, such as increased temperature or oxidative stress.  Conditional mutations are a type of mutation that manifest wild-type (or less severe) phenotype under certain permissive conditions (such as environmental), but manifest mutant phenotype under certain nonpermissive conditions. For example, a temperature-sensitive mutation can cause cell death at high temperature (nonpermissive condition), but might have no deleterious consequences at a lower temperature (permissive condition).

Various Types of Mutations Have Been Found in DNA from Damaged