複選題

25.For the statements of various biological processes in different cell compartments, which statement is (are) TRUE
(A) Nucleolus is located in the nucleus
(B) rRNA are made in the cytoplasm
(C) RNA synthesis takes place in the cytoplasm
(D) DNA replication takes place in nucleolus
(E) Mitochondria has its own DNA

21. Which of following statements for nucleic acid is (are) TRUE: (A) C, T are Purines (B) There are three hydrogen bonds between CG pairing (C) During the process of free nucleotides becoming RNA, every single nucleotide added, two phosphate groups are released. (D) The higher the GC content, the lower the Tm value is. (E) RNA at neutral pH buffer (pH=7) has no charge

22. What the followings are True when one design a set of primer for cloning: (A) Introducing extra sequences that would give us a restriction site in primer can be added at either 5' or 3' end of primer (B) Annealing temperature should only consider the sequence that could based paired with the target gene (C) Only if a N-terminus protein tag has been introduced into vector backbone, one should consider whether introduced restriction sites in the primer result in frame shift in the final protein products (D) Length of primer can be as short as 5 nucleotides (E) As long as melting temperature reaches to the target temperature, nucleotide composition is not affect the primer efficiency

複選題23. Which of the following statements for mRNA is (are) TRUE: (A) Prior to 5' mRNA capping, there are three phosphate at 5' end of mRNA (B) Cap structure is dispensable for protein translation initiation in eukaryotic mRNA. (C) Poly（Ａ） tail of the mRNA is encoded in the DNA sequence (D) One eukaryotic mRNA corresponding to one gene whereas one prokaryotic mRNA containing multiple gens. (E) RNA splicing is one of the first discovered enzymatic reaction that can be catalyzed by Ribozyme.

複選題24. Which of the following statements is (are) TRUE: (A) tRNA are transcribed by RNA polymerase II (B) Pre r-RNA are transcribed by RNA polymerase I (C) mRNA are transcribed by RNA polymerase III (D) long noncoding RNA are transcribed by RNA polymerase III (E) microRNA precursors are transcribed by RNA polymerase II

26. Which of the following amino acid residues has polar side chain: (A) Arginine (B) Asparagine (C) Phenylalanine (D) Lysine (E) Tryptophan

複選題27. Which of following statement is (are) TRUE: (A) Hydrophobic means it is water-like (B) Nucleic acid dissolved in water is because it is a negatively charged molecule. (C) Sodium acetate solution can not neutralize the charge of nucleic acid (D) The principle of ethanol precipitation is based on nucleic acid is not able to dissolved in ethanol (E) Most denatured proteins are water soluble

複選題28. What of the following statements is (are) TRUE: (A) Regardless Prokaryote or Eukaryote, ribosome is responsible for protein synthesis (B) An actively translated mRNA often has one ribosome on the mRNA (C) Eukaryote mRNA often forms in a circle to facilitate translation (D) There is one three-nucleotide sequence corresponding to stop codon (E) E site in ribosome responsible for polypeptide elongation

複選題29. What of the following statements is (are) TRUE: (A) Since there are 20 amino acids, there are 20 different tRNAs in the cell. (B) Despite the sequence differences within all tRNAs, all tRNAs have very similar tertiary structure (C) Only aminoacyl tRNA can be used in ribosome mediated polypeptide elongation. (D) No enzyme is required for tRNA amino acid addition (E) Upon tRNA is transcribed, tRNA can be used to incorporate amino acid

複選題30.CRISPR is a famous genome-editing tool. Which of following statement is (are) TRUE: (A) CRISPR is discovered as a bacterial immune system (B) There are multiple types of CRISPR (C) Two major components that introduced into mammalian cell for genome editing are cas-9 protein and guide DNA (D) Creating gene deletion using CRISPR rely on the mistake of DNA repairing system in the host cell (E) The recognition sequence for the cas-9 crispr system is the three nucleotide PAM sequence

31.There are 45 different kinds tRNA (anticodons) available to serve as amino acid carriers, but there are 64 mRNA codons. Why aren't the tRNA anticodons and mRNA codons equal in number? (A) The reason is that some tRNA anticodons can misread some of the mRNA codons, which creates a "wobble" in the tRNA anticodons that can be repaired by RNA repair enzymes. (B) The reason is that the third base pair on the mRNA codon allows some flexibility (wobble)； thus, some tRNA anticodons can recognize more than one mRNA codon. (C) The reason is that the third base pair on the tRNA allows some flexibility (wobble)； thus, some tRNA anticodons can recognize more than one mRNA codon. (D) The reason is that the tRNA has the flexibility to choose which mRNA codons are necessary for building the polypeptide chain. (E) This broader recognition occurs because of the nonstandard pairing between bases in the wobble position corresponding to the 3' base in the mRNA and the complementary 5′ base in the tRNA anticodon.