Question

Question 7 2 pts Which of these genes would not likely be regulated by the bacterial SOS response?! Translesion DNA polymerase Cell division promoter Holliday junction branch migration enzyme Nucleotide excision repair enzyme Question 8 2 pts Which of these mutations is likely to have the greatest impact on the amino acid composition of the resulting protein? Silent Synonymous Frameshift Missense

Answer 1

ANS.7 (B) cell division promotor

In E. coli, DNA damage and replication perturbations results in the SOS response, a genetic program that transcriptionally up-regulates over 50 unlinked genes. when he postulated the existence of the pathway on the basis of a set of physiological responses induced by DNA damage whose regulation was controlled by the lexA+ and recA+ gene products. cell division promotor is not envolve.

ANS.8 (C) frameshift mutations occure

type of mutation (insertion, deletion, or substitution) appears to have the most significant impact on an amino acid sequence. Insertions and Deletions – they cause frameshifts!

ANS.9 (B) transcription of the lac operon would become cAMP independent

The structural genes within the lac operon the will be constitutively transcribed. ... The catabolite activator protein becomes inactivated and no transcription occurs. The cAMP level rises in the absence of allolactose, which in turn inactivates the transcription.

ANS.10 (A)

Deficiencies in DNA repair enzymes are occasionally caused by a newly arising somatic mutation in a DNA repair gene, but are much more frequently caused by epigenetic alterations that reduce or silence expression of DNA repair genes

ANS.11 (C) chicken foot

Replication forks stalled at lesions (depicted by the shaded square) on the DNA can regress by reannealing the parental strands (shown in bold lines). The daughter strands (shown in thin lines) are also annealed as regression continues, leading to formation of a Holliday junction (“chicken-foot”) intermediate.

ANS.12 (A)

ANS.13(B) binding of general transcription factors binds to the promoter

Eukaryotes require transcription factors to first bind to the promoter region and then help recruit the appropriate polymerase. RNA Polymerase II is the polymerase responsible for transcribing mRNA.

Initiation. The initiation of gene transcription in eukaryotes occurs in specific steps. First, an RNA polymerase along with general transcription factors binds to the promoter region of the gene to form a closed complex called the preinitiation complex.