15. The_____element in the chromosome can stop the spreading of heterochromatin and prevent the effect of an enhancer on genes located on other side.
(A) insulator
(B) promoter
(C) centromere
(D) initiator

11. The genomic organization of a gene with 3 exons is shown below. The exons are shown as 3 boxes and their boundaries are denoted according to their location in mRNA. The size of the introns as well as location of start and stop codons are also shown on the top. If one wants to detect its expression level with the primer set a/h, what will be the closest size of its PCR product? (A) 15 kb (B) 500 bp (C) 10 kb (D) 800 kb ATG TAA +1 +500 10 kb +501 +1100 +1101 +1400 20 kb

12. Following question 11, the part of exon 1 between TAA and +1400 is called as: (A) terminator (B) 5'-UTR (C) 3'-UTR (D) initiator

13. Reverse transcriptase is an enzyme that can use RNA as a template to synthesize single strand DNA. As like all DNA polymerase, it needs a primer for the initiation of polymerization. If one wants to detect the expression levels of several protein-coding genes in mammalian cells with RT-PCR, which of the following primers is best for his reverse transcription reaction? (A) 5'-AAAAAAAAAAAAAAA-3' (B) 5'-TTTTTTTTTTTTTTT-3 (C) 5'-TATATATATATATATA-3 (D) 5'-ATGATGATGATGATG-3

14. Which of the following elements/genes is not included in the immunity region of lambda phage genome? (A)(B)cl (C) (D)CII

16. In a replication fork, you can find _____. (A) Okazaki fragments in the leading strand (B) one DNA polymerase synthesizing new DNA of both strands (C) DNA primase making DNA primer (D) nascent DNA synthesized from 5' to 3' in the leading strand.

17. The primosome in a prokaryotic replication fork is formed by_____(A) topoisomerase/helicase (B) DNA polymerase/pirmase fragment/topoisomerase (D) DNA primase/helicase (C) okazaki

18. The _____ enzyme cuts single strand DNA to resolve the tension ahead of replication fork. (A) polymerase (B) primase (C) topoisomerase I (D) topoisomerase II

19. Digestion of chromatin with nuclease to cut the linker DNA between nucleosomes and then isolate DNA from nucleosomes will most likely get DNA ladder of _____ bp. (A) 200 (B) 500 (C) 700 (D) 1000

20. Deamination of 5-methyl cytosine will generate a _____ base. (A) G (B) A (C)T (D) U

21. XIAP is an inhibitor of caspases. How does it work? (A) It prevents the cleavage of prodomians from executioner caspases. (B) It has a RING domain, which blocks the active site of initiator caspases. (C) It uncoils zymogen granules before than be activated by executioner caspases. (D) It attaches ubiquitin to caspases so they get degraded before they are active.