25. Which of the following statements regarding Transposable elements (TEs) is correct?

(1) TEs are DNA sequences that have the ability to change their position within a genome.

(2) Retrotransposons mobilize through a RNA intermediate being reverse-transcribed by the reverse transcriptase encoded by the retrotransposons themselves.

(3) All DNA transposons are mobilized via DNA intermediates being cut-and-paste to new locations in the genome.
(A) (1) only
(B) (2) only
(C) (3) only
(D) (1) and (2)
(E) (2) and (3)

21. Which of the following statements regarding ER or Golgi structure or function is correct? (1) The synthesis of fatty acids and phospholipids takes place in the smooth ER. (2) Rough ER synthesizes all proteins to be secreted from a cell. (3) COPI coat proteins mediate anterograde transport between the Golgi apparatus and other organelles. (4) The Golgi stacks receive proteins and lipids from the endoplasmic reticulum (ER) by the cis cisternae. (5) The presence of clathrin mediates vesicular transport from trans-Golgi to endosome. (A) (1), (2), (3) and (4) (B) (1), (2), (4) and (5) (C) (2), (3), (4) and (5) (D) (1), (2), (3) and (5) (E) (1), (3), (4) and (5)

22. Which of the following statements regarding endocytosis is correct? (1) Receptor-mediated endocytosis requires microtubule. (2) Cholesterol-binding protein caveolin containing pits involves in clathrin-mediated endocytosis. (3) Clathrin-coated pits can concentrate large extracellular molecules that have different receptors responsible for the receptor-mediated endocytosis of ligands. (A) (1) only (B) (1) and (2) (C) (2) and (3) (D) (1) and (3) (E) All of above

23. Which of the following statements regarding cells of immune system is correct? (1) Cells in the innate immune system use Pattern recognition receptors (PRRs) to recognize molecular structures that are produced by microbial pathogens. (2) Dendritic cells, macrophages, monocytes, neutrophils and epithelial cells, all belong to the innate immune system. (3) Innate immune cells are also important mediators in lymphoid organ development and the activation of the adaptive immune system.  (4) Helper T cells only recognize antigens coupled to Class I MHC molecules, while Killer T cells and regulatory T cells only recognize antigens coupled Class II MHC molecules. (5) Helper T cells regulate both the innate and adaptive immune responses and help determine which immune responses the body makes to a particular pathogen. (A) (2), (3), (4) and (5) (B) (1), (2), (3) and (4) (C) (1), (2), (4) and (5) (D) (1), (3), (4) and (5) (E) (1), (2), (3) and (5)

24. Which of the following statements regarding RNA sequencing (RNA-seq) is correct? (1) RNA-seq can be used to perform transcriptional profiling, SNP identification, RNA editing and differential gene expression analysis. (2) RNA-seq can detect transcripts from organisms with previously undetermined genomic sequences. (3) RNA-seq sequencing adapters are added to each end of the RNA fragments before library preparation. (A) (1) only (B) (2) only (C) (3) only (D) (1) and (2) (E) (2) and (3)

26. Dr. Robert Roeder discovers three DNA-dependent RNA polymerases from developing sea urchin embryos in 1969. Which description about his study is incorrect? (A) RNA polymerase I is located in nucleoli. (B) RNA polymerase I and II are sensitive to a-amanitin. (C) RNA polymerase III synthesizes tRNA and rRNA 5S. (D) The purification of polymerases is interfered by the nucleosomes. (E) Dr. Roeder develops cell-free reconstitution systems to study transcription and finds other factors are needed for RNA transcription.

27. In humans it is estimated that at least 90% of the genome is transcribed, with only 2% translated into proteins. There are many non-coding RNAs in cells, and one class is long non-coding RNA (IncRNA). Which description is incorrect about IncRNAs? (A) LncRNAs are defined as transcripts longer than 200 nucleotides with no apparent protein-coding capacity. (B) They usually are spliced, capped and polyadenylated. (C) The circular RNA (circRNA) does not belong to IncRNAs. (D) They are poorly conservative. (E) One X chromosome inactivation in female is an effect of IncRNAS.

28. The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli. (A) There are lacZ, lacy and lacA genes in lac operon and they are transcribed independently. (B) The lac repressor encoded by lacl gene is constitutively expressed. (C) In the presence of glucose, the catabolite activator protein (CAP) is activated to increase LacZ expression. (D) Lactose is a disaccharide, which can be cleaved by LacZ into fructose and galactose. (E) RNA polymerase binds to operator in the absence of lactose.

29. The methods: (1). Northern blotting； (2). RT-qPCR； (3). Southern blotting； (4). RNase protection assay； (5). cDNA microarray；(6). RNA-seq. What can be used for RNA quantification? (A) (1), (2), (5) and (6) (B) (1), (2), (4), (5) and (6) (C) (1), (2), (3), (5) and (6) (D) (2), (3), (4), (5) and (6) (E) (2), (4), (5) and (6)

30. What is not the unfolding protein response? (A) IRE1 (Inositol-requiring protein 1) is phosphorylated and served as a kinase. (B) IRE1 is an RNase for specific splicing of Xbp1 mRNA. (C) PERK (RNA-like ER kinase) is activated to phosphorylate eIF2a (D) The translation of all proteins is shutdown. (E) ATF6 (activating transcription factor 6) is cleavaged and transported into nucleus.

31. Which component is NOT in the Crispr/Cas9 complex? (A) Cas9 nuclease (B) crRNA (C) TracrRNA (D) 5'-3' exonuclease (E) Protospacer adjacent motif (PAM)