15. The following methods can separate proteins based on their mass except?
(A) centrifugation
(B) ion exchange chromatography
(C) SDS polyacrylamide gel electrophoresis
(D) gel filtration chromatography
(E) native polyacrylamide gel electrophoresis

11.Signaling at synapses is usually terminated by (A) calcium influx. (B) potassium influx. (C) inhibitory neurotransmitters. (D) degradation or reuptake of neurotransmitters. (E) none of the above.

12. Which repair is considered as an error-free mechanism? (A) Homologous recombination (B) Non-homologous end-joining (C) Microhomology-mediated end-joining (D) Single strand annealing (E) Transcription-coupled DNA repair

複選題13. Which one participates in the adaptive immune response? (A) B cell (B) NK cell (C) T cell (D) Neutrophils (E) macrophages

14.Apoptosis differs from necrosis in that necrosis__________. (A) requires the reception of an extracellular signal. (B) causes DNA to fragment. (C) causes cells to swell and burst, whereas apoptotic cells shrink and condense. (D) involves a caspase cascade. (E) all of the above

16. While examining the crystal structure of a membrane protein, you find several phospholipid molecules bound to the protein. You know that these lipids .(1) are thought to help stabilize many membrane proteins.(2) may enhance the crystallization of the bound membrane proteins.(3) interact specifically with the protein.(4) can have head groups of various sizes and charges depending on the protein. (A) 1,2 and 3 (B) 2,3 and 4 (C) 1, 3 and 4 (D) 1 only (E) All

17. Many cells store lipids in droplets of varying sizes. These droplets ... (A) have mostly protein-free bilayer membranes. (B) are composed primarily of charged amphiphilic lipids. (C) are produced by and released from the Golgi apparatus. (D) are enclosed by a phospholipid monolayer (instead of a bilayer). (E) mostly store cholesterol and phospholipids.

18. Which of the following methods provides the most sensitive and accurate way of measuring and comparing mRNA levels of a set of genes expressed at relatively low levels in two different tissues. (A) PCR (B) Ribosome profiling (C) ChIP-seq (D) DNA microarray analysis (E) RNA-seq

19. Epigenetics is most concerned with: (A) changes in a person's genotype resulting from environmental influences. (B) the expression of a particular gene as influenced by external inputs. (C) environmental influences on gene expression over experiential influences. (D) the heritability of genotypes that have been altered over multiple generations. (E) the DNA sequences or the chromatin structures that have been altered by external inputs.

20. An RNA-dependent DNA polymerase that carries the RNA template with it to synthesize repeats at the 3'-ends of chromosomes is called: (A) DNA ligase (B) telomerase (C) DNA polymerase y (D) topoisomerase (E) DNA polymerase B

21. The steroid hormone glucocorticoid can enter cells and bind with glucocorticoid receptor (GR) to regulate gene expression. Which is incotrect? (A) GR is in the cytoplasm in the absence of glucocorticoid. (B) GR is a leucine-zipper-containing transcription factor. (C) Glucocorticoid-bound GR can form a homodimer to bind to GREs. (D) GR serves as a transcription activator or inhibitor depending on the gene context. (E) GR inhibits the expression of cytokine genes by tethering other transcription factors such as AP1 and NF-kB.