#Question id: 3632
#SCPH28 | Zoology
geneticist is working with a new bacteriophage called phage Y3 that infects E. coli. He has isolated eight mutant phages that fail to produce plaques when grown on E. coli strain K. To determine whether these mutations occur at the same functional gene, he simultaneously infects E. coli K cells with paired combinations of the mutants and looks to see whether plaques are formed. He obtains the following results. (A plussign means that plaques were formed on E. coli K; a minussign means that no plaques were formed on E. coli K.)
How many cistron belong to these mutation?
#Question id: 15818
#SCPH01 Biochemistry
You and your lab partner have isolated 20 new mutant yeast strains that are defective in synthesis of threonine, an amino acid. These Thr- mutants do not grow on minimal medium, but they do grow on minimal medium supplemented with threonine. Ten of your Thr- mutants (numbered 1 through 10) were isolated in a strain of mating type a (MAT a). The other 10 Thrmutants (numbered 11 through 20) were isolated in a strain of mating type α (MAT α). You and your lab partner cross each of the MAT a strains to each of the MAT α strains, and you include crosses to the appropriate wild-type strains. Your experimental observations are shown in the table below, where (-) indicates diploids that did not grow on minimal medium and (+) indicates diploids that did grow on minimal medium.
What is the maximum number of genes that these 20 mutants could represent?
#Question id: 4354
#SCPH01 Biochemistry
Which of the following statements correctly describes the primary difference between enhancers and proximal control elements?
#Question id: 12686
#SCPH28 | Zoology
#Question id: 636
#SCPH05 I Biotechnology
DNA polymerase contains a lysine residue that is important for binding to DNA. Mutations were found that converted this lysine to either glutamate, glycine, valine, or arginine. Which mutations would be predicted to be the most and least harmful to the ability of the enzyme to bind DNA?
Most |
Least |
|
(A) |
Valine |
Aspartate |
(B) |
Glycine |
Arginine |
(C) |
Arginine |
Glycine |
(D) |
Glutamate |
Arginine |