24. What enables the splicing of group I and II introns?
(A) spliceosomes
(B) ribozymes
(C)snRNA
(D) poly-A tail

20. Okazaki fragments do which of the following? (A) assist in forming the replication fork (B) bind to the oriC region (C)assist in the synthesis of DNA from the lagging strand (D) reform the double-helix following replication

21. Which of the following is an example of a processive enzyme? (A) DNA polymerase I (B) DNA polymerase III (C)DNA ligase (D) Okazaki fragments

22. Most eukaryotic genes are collinear. (A) True (B) False (C)Because they are driven by a promoter (D) B and C are right

23. An R loop experiment was performed on two different mRNA's. The first showed one R loop, while the second showed two R loops separated by a region of double-stranded DNA. What is the composition of these two mRNA's? (A) The first contains no introns and the second two introns (B) The first contains no introns and the second one intron (C)The first contains one intron and the second two introns (D) The first contains two introns and the second one intron

25. Where does mRNA/tRNA codon-anticodon recognition take place? (A) 30S (B) 40S (C)50S (D) the surface between the two ribosomal subunits

26. With regard to Chapeville's experiment, what could not be the radioactive element used to label cysteine? (A) 15N (B) 35S (C)C (D) H

27. If a bacteria is placed in an environment that contains both glucose and lactose, the regulation of the lac operon will allow which nutrient to be processed first? (A) glucose (B) lactose (C)Both will be processed equally (D) Neither will be processed in this environment

28. The regulation of protein function, not gene expression, is called _____ regulation. (A) posttranslational (B) transcriptional (C)translational (D) post-transcriptional

29. Translational regulatory proteins recognize specific areas of what molecule? (A) tRNA (B) ribosome (C)rRNA (D) mRNA

複選題30. Histone acetyltransferases would be directly involved in which of the following? (A) formation of open chromatin (B) movement of the nucleosome (C)acetylation of lysines (D) termination of gene expression