QOuestion1Whatdotelomeresdo?a.They protectthe chromsomesfromdegradationbynucleases.b.They prevent the ends of chromosomesfrom fusing with one another.c.They arerequiredfor completechromosomalreplicationd.allof theabove2For each of thefollowing sentences, fill inthe blanks withthebest word or phraseselected from the list below.Not all words or phrases will be used; each word or phraseshould be used only once.Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, alleucaryotic cells have a , usually the most prominent organelle in the eucaryotic cell.Another organelle found in essentially all eucaryotic cells is the, which generates thechemical energy for the cell. On the other hand, a(n),can be found only in the cells ofplants and algae, and performs photosynthesis. If we were to strip away the plasmamermbrane from a eucaryotic cell and remove all of its membrane-enclosed organelles, wewould be left with the, which contains many long, fine filaments of protein that areresponsible for cell shape and structure and thereby form the cell's(a) chloroplast (d) cytosol (ac) nucleus(b)chromosome (e) endoplasmic reticulum (ad) ribosomes(o)cytoskeleton(ab)mitochondrion
1 1. What do telomeres do? a. They protect the chromsomes from degradation by nucleases. b. They prevent the ends of chromosomes from fusing with one another. c. They are required for complete chromosomal replication. d. all of the above Question 2、For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once. Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, all eucaryotic cells have a_, usually the most prominent organelle in the eucaryotic cell. Another organelle found in essentially all eucaryotic cells is the _, which generates the chemical energy for the cell. On the other hand, a(n) _,can be found only in the cells of plants and algae, and performs photosynthesis. If we were to strip away the plasma membrane from a eucaryotic cell and remove all of its membrane-enclosed organelles, we would be left with the _, which contains many long, fine filaments of protein that are responsible for cell shape and structure and thereby form the cell’s _, (a) chloroplast (d) cytosol (ac) nucleus (b) chromosome (e) endoplasmic reticulum (ad) ribosomes (c) cytoskeleton (ab) mitochondrion
Answer:1、D2、 Eucaryotic cells are bigger and more elaborate thanprocaryotic cells. By definition, all eucaryotic cells have anucleus, usually the most prominent organelle in theeucaryotic cell. Another organelle found in essentially alleucaryotic cells is the mitochondrion, which generates thechemical energy for the cell. On the other hand, a(n)chloroplast can be found only in the cells of plants and algaeand performs photosynthesis. If we were to strip away theplasma membrane from a eucaryotic cell and remove all of itsmembrane-enclosed organelles, we would be left with thecytosol, which contains many long, fine filaments of proteinthat are responsible for cell shape and structure and therebyform the cell's cvtoskeleton2
2 Answer: 1、D 2、Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, all eucaryotic cells have a nucleus, usually the most prominent organelle in the eucaryotic cell. Another organelle found in essentially all eucaryotic cells is the mitochondrion, which generates the chemical energy for the cell. On the other hand, a(n) chloroplast can be found only in the cells of plants and algae, and performs photosynthesis. If we were to strip away the plasma membrane from a eucaryotic cell and remove all of its membrane-enclosed organelles, we would be left with the cytosol, which contains many long, fine filaments of protein that are responsible for cell shape and structure and thereby form the cell’s cytoskeleton
一、判断1.亮氨酸拉链基元是反式作用因子的一种特异性亮氨酸序列，它们通过二聚体的形式形成拉链结构参与基因表达的调节2.核小体的核心蛋白由H1、H2A、H2B、H3各两个分子组成的八聚体。3.在减数分裂过程中,染色体间发生的分子重组是随机发生的。答：T;答：E，H1不参与核小体核心蛋白的装配答：F，同源染色体间的分子重组是随机发生的3
3 1. 亮氨酸拉链基元是反式作用因子的一种特异性 亮氨酸序列, 它们通过二聚体的形式形成拉链 结构参与基因表达的调节。 2. 核小体的核心蛋白由H1、H2A、H2B、H3各 两个分子组成的八聚体。 3. 在减数分裂过程中,染色体间发生的分子重组是 随机发生的。 一、判断 1. 答: T; 2. 答: F, H1不参与核小体核心蛋白的装配。 3. 答: F, 同源染色体间的分子重组是随机发生的
组蛋白可发生四种形式的修饰，其中与转录有关的修饰作4用是甲基化。这种染色体被某些染色体或染色体片段具有异固缩现象，成为异染色质同一个体不同组织的细胞中，核仁的大小和数自都有很大-的变化，这种变化和细胞中蛋白质合成的旺盛程度有关。7.组蛋白是碱性蛋白，带正电荷，功能是参与核小体的构建。其中H1位于两个核小体的连接DNA的中间部位，主要起连接作用。答：F是乙酰化。答：T;5答：T;答：FHI位于缠绕核心组蛋自DNA的入口处。7
4 4. 组蛋白可发生四种形式的修饰,其中与转录有关的修饰作 用是甲基化。 5. 某些染色体或染色体片段具有异固缩现象, 这种染色体被 成为异染色质。 6. 同一个体不同组织的细胞中, 核仁的大小和数目都有很大 的变化, 这种变化和细胞中蛋白质合成的旺盛程度有关。 7.组蛋白是碱性蛋白, 带正电荷, 功能是参与核小体的构建。 其中H1位于两个核小体的连接DNA的中间部位，主要起连 接作用。 4. 答: F, 是乙酰化。 5. 答：T; 6. 答：T; 7. 答：F, H1位于缠绕核心组蛋白DNA的入口处
DNA在进行半保留复制时核小体组蛋白也要解聚8.复制后再进行组装但不参与折叠或装配分子伴侣帮助多肽链转运福最终产物的形成。引导蛋白质定位10.核定位信号同信号肽和导肽一样，后通常要被切除答：EDNA复制时，核小体的组蛋白核心是全保留的。9. 答： T;10：答：F，核定位信号是永久性的，不会被切除5
5 8. DNA在进行半保留复制时, 核小体组蛋白也要解聚, 复制后再进行组装。 9. 分子伴侣帮助多肽链转运、折叠或装配, 但不参与 最终产物的形成。 10.核定位信号同信号肽和导肽一样, 引导蛋白质定位 后通常要被切除。 8. 答：F, DNA复制时, 核小体的组蛋白核心是全保留的。 9. 答：T; 10. 答: F, 核定位信号是永久性的, 不会被切除