29. Picornavirus mRNAs are not capped, yet they can still out compete host mRNAs for binding to the ribosome by
(A) having a stronger affinity for the ribosome.
(B) degrading host mRNA.
(C) inactivating host Cap binding protein, eIF4F.
(D) inactivation of host RNases.
(E) inactivation of host Cap binding protein, eIF2B.

25. Dr. Roger Komberg (Stanford University) used structural basis to reveal the mechanism of        nucleotide selection       in the posttranslocation state of eukaryotic RNA polymerase II. Which of the following statement is       not true      ? (A) The study reveals two distinct nucleotide-binding sites, the E and A sites, at the active center of RNA polymerase II (B) The E site is the location where incoming nucleotide first encounters (C) The A site is the location where phosphodiester bonds form (D) Rotation of nucleotide between the E and A sites may be helpful for base specificity (E) Rotation of nucleotide between the E and A sites may be affect the specificity for deoxyribonucleotides as opposed to ribonucleotides

26. Which of the following statement related to the nuclear receptor is       not true      ? (A) Thyroid hormone receptor belongs to type I receptors, which stay in the cytoplasm in the absence of its ligand (B) Type III receptors are "orphan" receptors whose ligands are not yet identified (C)In the presence of ligand, the glucocorticoid receptor (GR) can form a homodimer within the nucleus (D)In the absence of ligand, GR exists as an inactive form in cytoplasm complexed with the heat shock protein 90 (Hsp90) (E) Nuclear receptors interact with different endocrine-signaling molecules and activate gene expression via its binding to hormone response DNA elements

27. Predict the consequence of treating the 70S ribosomal with urea: (A) the RNA portion would be degraded. (B) the unit would be undisturbed. (C) the protein component would be degraded. (D) the unit would dissociate RNA and protein components. (E) the treatment would lead to tighter association between RNA components.

28. Which of the following is not part of the 30S initiation complex? (A) IF1, IF2, and IF3 (B) 5S rRNA (C) 16S rRNA (D) amino-acyl tRNA (E) mRNA

30. EF-Tu is an important protein in cells whose function is to (A) properly fold proteins. (B) ensure proper ribosome assembly. (C) escort aminoacyl-tRNA to the ribosome. (D) protect rRNA from degradation by RNases. (E) stabilize mRNA within the ribosome. 

1. A Double-stand DNA can be peeled off by a _____ to become 2 single-strand DNAs. (A) DNA polymerase (B) helicase (C) RNA polymerase (D) ligase

2. DNA replication normally occurs at the _____ phase of cell cycle. (A) S (B) G1 (C) G2 (D) M

3. The catalytic center of a prokaryotic RNA polymerase is formed by _____(A)oa (B) Ba (C) yy (D) BB

4. Linear chromosomes are protected from replicative senescence by a stretch of repetitive sequence called _____ and the enzyme that synthesizes it. (A) telomere (B) centromere (C) promoter (D) replication origin

5. The one recombinase employed in the bacteria homologous recombination is _____  (A) RecA (B) CRE recombinase (C) Flippase (D) Spo11