Question

The inheritance of the petite phenotype in Saccharomyces cerevisiae is complicated by an interaction of mitochondrial and nuclear genes. Which of the following is a false statement about petites in S. cerevisiae?
A) Segregational petites are characterized by mutations in the nuclear genome.
B) Suppressive petites are characterized by mitochondria lacking most of its DNA.
C) Neutral petites, when crossed to wild type, yield wild-type mitochondrial function.
D) The three categories of petites are segregational, neutral, and suppressive.
E) Both nuclear and cytoplasmic (mitochondrial) genes contribute to the petite phenotype in some cases.

Answer 1

Answer:

Option B

Explanation:

The three categories of petites are segregational, neutral, and suppressive and both nuclear and cytoplasmic (mitochondrial) genes contribute to the petite phenotype in some cases. Suppressive petites are characterized by perfoming crosses between petite and wild-type and discovering that all offspring are petite, this exhibit a "dominant" behavior which suppresses wild-type mitochondrial function and not a lack of mitochondrial function.