21.The cell metabolism is tightly connected to the regulation of gene expression. The lac operon (lactose operon) is an example. Which statement below regarding the lac operon is correct?
(A)There are lacZ, lacY and lacA genes in lac operon and they are transcribed ind

(B)RNA polymerase binds to operator in the absence of lactose.

(C) The operon is controlled by negative and positive transcription factors.

(D) In the presence of lactose, the lac repressor encoded by the lacI gene is not expressed for ope

ron activation.
(E) In the presence of high concentration glucose, the catabolite activator.protein (CAP) is activated to increase Lac Zexpression.

17.The Agel restriction enzyme recognizes the sequence ACCGGT and cuts each strand between the first ( A ) and the second ( C )nucleotide. This can be represented as A|CCGGT, with the vertical bar indicating the cleavage position. If a DNA ,fragment is cut with Agel at both ends, cutting a plasmid with which of the following enzymes would then allow insertion ofthe fragment into the plasmid by simple ligation of sticky ends? (A) MroI, with the recognition sequence T|CCGGA (B) Aatl, with the recognition sequence AGG|CCT (C) BstZI, with the recognition sequence C|GGCCG (D) FseI, with the recognition sequence GGCCGG|CC (E) None of the above

18.Is sequencing, does each labeled DNA molecule have a fluorescently labeled dideoxyribonucleotide end? Do the labeled nucleotides lack the 2' or 3' hydroxyI group? (A) 3' end； 2' hydroxyl group only (B) 3' end； 3' hydroxyl group only (C) 5' end； 2' hydroxyl group only (D) 5' end； 3' hydroxyl group only (E) 3' end； both hydroxyl groups

19.The DNA-binding proteins that recognize and accurately initiate transcription at specific eukaryotic promo called: (A) enhancers (B) transcription factors (C) response elements (D) chromatin-remodeling complexes (E) All are true

20. Functional DNA is not found in: (A) bacterial nucleoids(B)chloroplasts(C)lysosomes(D) mitochondria(E)nuclei

22.The 2019 Nobel Prize in Physiology or Medicine was awarded to three scientists for discovering hypoxia-ind transcription factor that regulates gene expression in response to decreases in cellular oxygenation. Unde n, HIF1a-HIF 1β heterodimer bonds to target genes' HRE (hypoxia-tesponse element), leading to gen ygen condition, HIF 1a is hydroxylated in two ( residues and recruits E3 () ligase for protein deg the three blanks? (A) Activation, proline, ubiquitin. (B) Inhibition, proline, ubiquitin. (C) Activation, histidine, ubiquitin. (D) Inhibition, histidine, SUMO. (E) Activation, proline, SUMO.

複選題23. Translation defines the cellular proteome； which statement is correct? (A) Translational control has nothing to do with mRNAs. (B) The Cer4-Not complex affects mRNA translatability. (C) The elongation of translation is a uniform process. (D)Ribosome pausing increases translation efficiency. (E) The regulation of translation is independent of cell status and environment.

24.Consider the canonical nuclear localization sequence (cNLS) mediated protein transport mechanism； which statement is correct? (A) The cargo-carrier import complex is assembled in the nucleus. (B) The cargo protein utilizes its cNLS direct contact with the importinβ. (C) The RanGDP protein is more concentrated within the cytoplasm than the nucleus in preparation for cargo protein transport. (D) The RanGDP protein is essential to export the importin from the nucleus. (E) The cargo protein translocation is through the nuclear pore complex in the endoplasmic reticulum.

25. Vesicular transport describes vesicles bud off from one compartment and fuse with another. Most transport vesicles form from specialized, coated regions of membranes. They therefore bud off as coated vesicles. Which statement(s) is correct regarding coated vesicles?(1) Clathrin-coated vesicles mediate transport originating from the Golgi apparatus, endosome, and the plasma membrane. (2) COPI-coated vesicles contribute to the ER-to-Golgi transport, comprising large protein subcomplexes that are made of seven different protein subunits.(3) The retromer complex has been shown to mediate retrieval of various transmembrane receptors, such as the cation- independent mannose 6-phosphate receptor. (A) (3) only (B) (I) and (2) (C) (2) and (3) (D) (1) and (3) (E) All of above are correct.

26. Which of the following statement(s) is cotrect regarding to protein endocytosis or exocytosis? (1)Clathrin-mediated endocytosis involves cargo recognition and coat assembly, followed by membrane inv finally pinching off to deform membranes.(2) Proteins being internalized move to the lysosome and recycling endosome for protein degradation and reuse, respectively.(3) Neurotransmitters are typically released from synaptic vesicles into the synaptic clett via exocytosis, which is the fusion of vesicles with the plasma membrane. (A) (1) and (2) (B) (2) and (3) (C) (1) and (3) (D) (3) only (E) All of above are correct.

27. Which of the following statements regarding stem cells (SCs) is correct?(1) A stem cell can divide to one copy of itself and to one differentiated cell.(2) The pluripotent SCs showed higher differentiation potency than the totipotent and multipotent SCs.(3) Stem cells could be used to test new drug. (A) (1) (B) (2) (C) (3) (D) (1) and (3) (E) (2) and (3)