Strain of Aspergillus was subjected to mutagenesis by X rays
Not what you're looking for?
A strain of Aspergillus was subjected to mutagenesis by X rays, and two tryptophan-requiring mutants ( A and B) were isolated. These tryptophan-requiring strains were plated in large numbers to obtain revertants to wild type. You failed to recover any revertants from mutants A and recovered one revertant from mutant B. This revertant was crossed with a normal wild-type strain. What proportion of the progeny from this cross would be wild type if
a) the reversion precisely reversed the original change that produced the typ- mutant allele?
b) the revertant phenotype was produced by a mutation in a second gene located on a different chromosome (the new mutation suppresses trp-)?
Propose an explanation of why no revertants from mutant A were recovered.
Purchase this Solution
Solution Summary
The expert examines the strain of Aspergillus was subjected to mutagenesis by X-rays. The reversion precisely reversed the original change that produced the typ- mutant allele is determined.
Solution Preview
(a) If the revertant precisely reversed the original mutation that produced the typ- mutant, then clearly, the revertant is completely wild type in the original way, not just wt with respect to phenotype, but wt with respect to genotype as well. Get my point? In other words, if the revertant reversed the mutation exactly like it was before the mutation occurred, then it's totally normal in every way. Thus, if this revertant is mated with a wt ...
Purchase this Solution
Free BrainMass Quizzes
Human Anatomy- Reproductive System
Do you know your reproductive anatomy?
Comfort Measures For Labor
Are you ready to doula someone through labor?
How Well Do You Know Your Body?
This quiz will assess the different systems of the human body. It will examine everything from the organs to the cellular processes that occur.
Vision and Oculomotor Control
This quiz will test the student's knowledge of the neural underpinnings of the visual system and its central pathways.
Feeding Babies
Do you know the science behind feeding babies? Test your knowledge with this quiz.