单选题A．DNAB．mRNAC．rRNAD．hnRNAE．tRNA

单选题关TDNA复制方向性的叙述哪一项是正确的

单选题蛋白质在等电点时是

单选题决定糖酵解途径最主要的是(　　　)

单选题已知基因A和B都是X连锁的，下列何种杂交所得的子代能确定位点间的重组率(假定雄性是异配性别，而且两性别均可发生交换)。______ A.雌AB/ab×AB/Y雄 B.雌Ab/aB×ab/Y雄 C.雌ab/AB×Ab/Y雄 D.上述各种杂交都不对

单选题下列是关于氧化呼吸链的捕述，错误的是 A.递氢体同时也是递电子体，递电子体不一定是递氢体 B.在传递氢和电子过程中，可偶联ADP磷酸化 C.CO可使整个呼吸链的功能丧失 D.呼吸链的组分通常按ΔG°'值由小到大的顺序排列 E.线粒体DNA突变可影响呼吸链功能

单选题The question of whether war is inevitable is one which has concerned many of the world's great writers. Before considering this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which social entities function in the disservice of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the service of one another. These definitions are necessary because it is important to emphasize that competition between individuals or groups is inevitable in a world of limited resources, but conflict is not. Conflict, nevertheless, is very likely to occur, and is probably an essential and desirable element of human societies. Many authors have argued for the inevitability of war from the premise that in the struggle for existence among animal species, only the fittest survive. In general, however, this struggle in nature is competition, not conflict. Social animals, such as monkeys and cattle, fight to win or maintain leadership of the group. The struggle for existence occurs not in such fights, but in the competition for limited feeding areas and for occupancy of areas free from meat-eating animals. Those who fail in this competition starve to death or become victims to other species. This struggle for existence does not resemble human war, but rather the competition of individuals for jobs, markets, and materials. The essence of the struggle is the competition for the necessities of life that are insufficient to satisfy all. Among nations there is competition in developing resources, trades, skills, and a satisfactory way of life. The successful nations grow and prosper; the unsuccessful decline. While it is true that this competition may induce efforts to expand territory at the expense of others, and thus lead to conflict, it cannot be said that war-like conflict among nations is inevitable, although competition is.

单选题下列哪种碱基，只存在于RNA而不存在于DNA中?( )

单选题脂肪合成的场所是

单选题氮杂丝氨酸能干扰或阻断核苷酸合成是因为其化学结构类似于

单选题密码子中表现为简并性(摇摆)的碱基对是( )。

单选题生长调节素(somatomedin)是______。

单选题NADPH + H + 的主要作用不包括

单选题密码子是哪一水平的概念______ A.DNA B.rRNA C.tRNA D.mRNA E.snRNA

单选题干扰素指的是 A.病毒本身存在的物质 B.细菌产生的物质 C.根据竞争性抑制原理设计的物质 D.病毒感染后诱导细胞合成的物质 E.抗生素中的一种

单选题关于线粒体内膜外侧的H+转运的描述，正确的是 A.H+可以通过ATP合酶的质子通道顺浓度梯度转移 B.线粒体外侧浓度低于线粒体内的H+浓度 C.H+可自由进入线粒体 D.H+经内膜进入线粒体内释放化学能 E.当质子顺梯度回流时，释放的全部能量被ATP合酶利用合成ATP

单选题胆固醇来源于磷酸戊糖途径的合成原料是

单选题泛素化蛋白质主要在______中降解。

单选题为了验证σ因子循环假说，Ebright等人采用______技术测定σ因子相对DNA某一位点的距离。

单选题膜固有蛋白和膜脂的相互作用主要通过______。