2000 500 atoxin 000- Guanine The TA 100 and TA 1538 are his Salmonella bacterial
ID: 145382 • Letter: 2
Question
2000 500 atoxin 000- Guanine The TA 100 and TA 1538 are his Salmonella bacterial strains sensitive to reversion mutations by base substitutions and frameshifts, respectively Aflatoxin is a mutagen that binds to G bases and induces apurinic sites in TA1538 DNA. 20 40 60 8 100 Afiatoxin B, dose ing) Please answer the following question(s): 1. The graph shows the results of an Ames test to identify the the effect of several concentrations of Aflatoxin B using a couple of his- Salmonella strains (TA 100 and TA 1538). While TA 100 is a strain sensitive to reversion mutations by base substitutions, TA 1538 is sensitive to frameshift mutations. Based on the results, what kind of mutations can Aflatoxin 81 lead to? O a. Missense mutations b. Nonsense mutations c. Frameshift mutations d. Regulatory mutations e. All except frameshift mutationsExplanation / Answer
In the above experiment, increasing amount of Aflatoxin B1 induces Substitution mutation in TA100 strain but not frameshift mutation in TA1538 strain.
TA100 strain is his- ,
it cannot produce histidine and hence cannot grow in histidine free medium. After mutation at GC pair, it reverted to his+ that is now it can grow in histidine free medium. This is missense mutation where change in one base pair leads to change in aminoacid production.
TA1538 shows a flat line that means it was not mutated by frameshift mutation to revert to his+.
KINDLY GIVE RATING
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.