8. In prokaryotes, a promoter has consensus sequences typically located at and (

Question

8. In prokaryotes, a promoter has consensus sequences typically located at and (A) -25,-75 (B) -25,-35 (C)-10, -25 (D)-10, -35 (E)-10,-75 9. The protein responsible for binding the consensus sequences in question 8 is (A) beta factor (B) sigma factor (C) TBP (D) alpha factor (E) none of the above 10. Base-pair substitutions involving the third base of a codon are unlikely to result in an error in the polypeptide. This is because (A) substitutions are corrected before transcription begins (B) substitutions are restricted to introns (C) the base-pairing rules are less strict for the third base of codons and anticodons (D) a signal-recognition particle corrects coding errors (B) transcribed errors attract snRNPs, which then stimulate splicing and correction I1. Lagging strand synthesis involves (A) Okazaki fragments (B) Shine-Dalgarno fragments (C) Klenow fragments (D) restriction fragments 12. When a messenger RNA molecule arrives at the ribosome, (A) it binds to the A-site (B) it binds to the P-site (D) it binds to the 23S RNA in the large subunit (C) ?t binds to the 16S RNA in the small subunit (E) it binds to the 5S RNA in the large subunit 13. In prokaryotes, rho-independent terminators are characterized by RNAs that have an structure followed by a (A) inverted repeat, poly(T) tract (B) inverted repeat, poly(G)tract (C) inverted repeat, poly(U) tract (D) direct repeat, poly(C) tract (E) direct repeat, poly(A) tract

Explanation / Answer

8. D

The -10 sequence is called as Pribnow box which has the usual sequence of TATAAT and -35 has the sequence of TTGACA.

9. B

Sigma factor is required for promoter recognition and binds the consensus sequence.

10. C

This is explained by wobble hypothesis in which the third base of a codon and the first base of an anticodon wobble.

11. A

The lagging strand is synthesized by DNA polymerases in short fragments called as okazaki fragments.

12. C

The 16S rRNA in prokaryotes is bound at its 3' region by Shine Dalgarno sequence of the mRNA.

13. B and E

Related Questions

Navigate

• Browse (All)
• Browse 8
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.