43. 設 且 ，則 x + y =？
(A) 21
(B) 24
(C) 27
(D) 28

複選題37. About microtubules, which of the following descriptions are correct? (A) Microtubules are associated with the microtubule-organizing center (MTOC) with their (-) ends, and the (+) ends of microtubules point away from the MTOC. (B) Treadmill (progressive growth) of microtubules requires ATP, with GTP-bound ẞ-tubulins added at the (+) ends of microtubules. (C) Kinesins are microtubule (-)-end-orineted motors, and dyneins are (+)-end-oriented motor proteins. (D) Microtubules go through alternating rescue (growing phase) and catastrophe (shrinking phase), a process known as the dynamic instability. (E) Microtubules determine the shape of a cell but do not function in regulating cellular polarity.

複選題38. About actin cytoskeleton, which of the following descriptions are correct? (A) At steady state of actin polymer formation, the concentration of monomeric actins is determined by the critical concentration Cc. (B) The rate-limiting step in actin polymerization is the elongation phase from a short actin oligomer to a long polymer. (C) ATP-G-actins add at both the (+) and the (-) ends, but adding of ATP-G-actins is faster at the (-) end. (D) Arp2/3 prevents actin polymers from growth, whereas capping proteins promote actin branching. (E) The small GTPases Rho, Rac and Cdc42 are critical regulators of actin dynamics. 39-40. Jared is studying how cell division is controlled, using the Xenopus (a kind of frog) fertilized oocytes

39. Which of the following experiments may NOT help Jared gain support for his hypothesis? (A) Compare the protein contents in unfertilized oocytes and fertilized oocytes; proteins existing in the latter but not in the former could be candidates for cell division-promoting factors. (B) Analyze the sperm proteins. Since the oocyte begins to divide after fertilization, the key element is in the cytoplasm of the sperm. (C) Separate the nucleus, cell membrane as well as the cytoplasm of fertilized oocytes, and add each of these individual components to the non-dividing cells. The prediction is that the fertilized oocyte cytoplasm should induce cell division when added to other non-dividing cells. (D) Do a pulse-labeling of newly synthesized proteins in the fertilized oocytes with radioisotopes, and compare protein radioactivities in the dividing v.s. non-dividing cells. This may help identify proteins that are associated with cell division cycles. (E) Do a genome-wide RNAi screen to identify the gene encoding the cytoplasmic factor that Jared is looking for.

40. Jared finally succeeded in isolating the protein cyclin B, showing that adding purified cyclin B alone to (A) In the cells, cyclin B synthesis is on and off. When cyclin B synthesis is turned off, cells do not divide. (B) There is another factor that may inhibit cyclin B activity during the non-division phase. (C) Non-dividing cells have an intrinsic factor that complexes with cyclin B and triggers cell division. After cell division is complete, the concentration of this factor is diluted and becomes inadequate for binding to cyclin B. As a result, the cell does not begin to divide unless the level of this intrinsic factor builds up again. (D) Cyclin B has a limited half life and when cyclin B is degraded, cell division does not occur. (E) Cyclin B is sensitive to the copy number of chromosome and is active only when the cell contains replicated DNA materials.

44. 若 a－b＞b－c＞a－c，則 a、b、c 三數的大小關係為何？ (A) c＞a＞b (B) c＞b＞a (C) b＞a＞c (D) a＞c＞b

45. 若多項式 A 為 x 的二次多項式、多項式 B 為 x 的三次多項式，則下列敘述何者      為真      ？ (A) A + B的和為 x 的五次多項式 (B) B − A 的差為 x 的一次多項式 (C) A × B的積為 x 的六次多項式 (D) B ÷ A的商為 x 的一次多項式

46. 果園裡種了 30 棵蘋果樹，平均每棵年產 400 個蘋果；若在此果園中每加種 一棵蘋果樹，平均每棵年產量會減少 10 個，則應種多少棵蘋果樹才能使年 產量最多﹖ (A) 25 棵 (B) 35 棵 (C) 45 棵 (D) 55 棵

47. 已知一弦把圓周分成兩弧，其中一弧的度數為另一弧的 1.5 倍，則此弦所對 的圓心角是幾度？ (A) 72 度 (B) 108 度 (C) 144 度 (D) 216 度

48. 某公園有四個不同的進出口，如果媽媽早上去公園運動，則她從不同一口進 出的方法有幾種﹖ (A) 6 種 (B) 12 種 (C) 16 種 (D) 24 種

49. 將自然數依序寫出如下的算式： 第 1 個算式：1+2 = 3 第 2 個算式：4+5+6=7+8 第 3 個算式：9+10+11+12 =13+14+15 按照此規律繼續寫下去的第 10 個算式之等號左側的數字總和是多少？ (A) 1025 (B) 1050 (C) 1155 (D) 1250