在一个DNA分子中，腺嘌呤与胸腺嘧啶之和占全部碱基数目的54％，其中一条链中鸟嘌呤与胸腺嘧啶分别占该链碱基总数的22％和28％，则由该链转录的信使RNA中鸟嘌呤与尿嘧啶分别占碱基总数的

试卷相关题目

• 1在自然界中，紫茉莉的枝叶有绿色、白色、花斑三种类型。下列关于紫茉莉枝叶颜色遗传的说法中正确的是

  A.同时含有白色体和叶绿体遗传物质的受精卵不一定发育成花斑植株

  B.只含叶绿体的受精卵不一定发育成绿色植株

  C.紫茉莉花斑植株的后代中一定有花斑植株

  D.紫茉莉枝叶颜色遗传的物质基础是质体DNA和线粒体DNA

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• 2农田中长期使用某种杀虫剂，结果害虫的抗药性增强，杀虫效果下降，原因是

  A.杀虫剂诱发了害虫抗药性基因的产生

  B.杀虫剂对害虫具有选择作用，使抗药性害虫的数量增加

  C.杀虫剂诱导害虫分解药物的基因大量表达

  D.抗药性强的害虫的后代都具有抗药性

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• 3人体线粒体突变基因引起的遗传病的特点是

  A.由基因控制，遵循孟德尔遗传定律，男性和女性中均可表现

  B.由基因控制，不遵循孟德尔遗传定律，男性和女性中均可表现

  C.属于细胞质遗传，不遵循孟德尔遗传定律，只在女性中表现

  D.属于细胞质遗传，不遵循孟德尔遗传定律，不出现性状分离

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• 4下列描述中除哪一项外，其余都是真核细胞与原核细胞基因结构的共同点

  A.编码区都能转录成RNA

  B.编码区都是编码蛋白质的序列

  C.非编码区对遗传信息的表达有调控作用

  D.非编码区有RNA聚合酶的结合位点

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• 5河流生态系统受生活污水轻度污染后，在自动净化并恢复原状的过程中，最后出现增长高峰的是

  A.藻类植物

  B.以细菌为食的原生动物

  C.细菌

  D.溶解在水中的有机物

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• 6基因型分别为AaBbCCDd和AaBbccdd的两种豌豆杂交，子代中表现型不同于亲本的个体所占的比例为（    ）

  A.5／8

  B.23／32

  C.9／32

  D.0

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• 7某自然生态系统中只有一条由四种生物构成的捕食链：甲→乙→丙→丁。在某一时刻测得这四种生物所含的有机物总量分别为a、b、c、d，下列相关的分析中正确的是

  A.甲从无机环境中获得的能量不一定大于a所含的能量

  B.丙种群个体对c的平均值肯定大于丁种群个体对d的平均值

  C.若b大于0.2a，此生态系统的稳定性肯定会遭到破坏

  D.这四种生物构成一个群落

  开始考试点击查看答案
• 8假设某生态系统中生产者只有一种植物，消费者只有一种动物，而且该植物的某条染色体上的基因A影响植物的存活能力和可食程度。植物的存活能力与可食程度的关系如下表，据此分析下列说法中正确的是 <table style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; BORDER-COLLAPSE: collapse; MARGIN-LEFT: 47.4pt; BORDER-TOP: medium none; BORDER-RIGHT: medium none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext" border="1" cellspacing="0" cellpadding="0" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 17.25pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 74.65pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt" width="100">基因型</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 60.55pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="81">AA</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 63.8pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="85">Aa</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 70.85pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="94">aa</td></tr><tr style="HEIGHT: 16.45pt; mso-yfti-irow: 1"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 74.65pt; PADDING-RIGHT: 5.4pt; HEIGHT: 16.45pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="100">存活能力</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 60.55pt; PADDING-RIGHT: 5.4pt; HEIGHT: 16.45pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="81">强</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 63.8pt; PADDING-RIGHT: 5.4pt; HEIGHT: 16.45pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="85">弱</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 70.85pt; PADDING-RIGHT: 5.4pt; HEIGHT: 16.45pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="94">极弱</td></tr><tr style="HEIGHT: 17.25pt; mso-yfti-irow: 2; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 74.65pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="100">可食程度</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 60.55pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="81">高</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 63.8pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="85">低</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 70.85pt; PADDING-RIGHT: 5.4pt; HEIGHT: 17.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="94">极低</td></tr></tbody></table>

  A.在若干世代的生活过程中，流入动物的能量全部来自于基因型是AA的植物

  B.经过若干世代后，该生态系统中的植物、动物的种群数量将达到动态平衡

  C.在该生态系统中植食动物是制约植物种群密度的唯一因素

  D.由于动物的制约该植物种群中，A基因的频率不会因植物成活能力的差异而发生改变

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• 9生物学能有今天的辉煌成就,离不开众多科学家倾其一生孜孜不倦的研究。下面提及的著名的科学家的实验中精心设置了对照实验的是（      ）①达尔文提出以自然选择学说为中心的生物进化理论②孟德尔通过豌豆杂交实验发现基因的分离定律和基因的自由组合定律③赫尔希和蔡斯证明在噬菌体中DNA是遗传物质，而蛋白质不是遗传物质 <table style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; BORDER-COLLAPSE: collapse; MARGIN-LEFT: 6.75pt; BORDER-TOP: medium none; MARGIN-RIGHT: 6.75pt; BORDER-RIGHT: medium none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext; mso-table-lspace: 9.0pt; mso-table-rspace: 9.0pt; mso-table-anchor-vertical: paragraph; mso-table-anchor-horizontal: page; mso-table-left: 441.9pt; mso-table-top: 13.1pt" border="1" cellspacing="0" cellpadding="0" align="left" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 14.5pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt" width="43">类别</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="36">Ⅰ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="28">Ⅱ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="36">Ⅲ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="33">Ⅳ</td></tr><tr style="HEIGHT: 14pt; mso-yfti-irow: 1"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="43">父亲</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="28">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="33">-</td></tr><tr style="HEIGHT: 6pt; mso-yfti-irow: 2"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="43">母亲</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="28">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="33">-</td></tr><tr style="HEIGHT: 13.5pt; mso-yfti-irow: 3"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="43">儿子</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+ -</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="28">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="33">+ -</td></tr><tr style="HEIGHT: 13.25pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="43">女儿</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+ -</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="28">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="33">-</td></tr></tbody></table>  ④艾弗里证明促使R型细菌转化成S型细菌的物质是DNA

  A.③④

  B.①③④

  C.②③④

  D.①②③④

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• 10调查人类的某种遗传病时，发现有如下图所示的四种类型的家庭（注：每类家庭数150～200，表中“+”为发现有该病的患者，“-”为未发现该病的患者）。以下所作的推断中，最科学的是

  A.第Ⅰ类家庭的结果说明此病一定属于X染色体显性遗传病

  B.第Ⅱ类家庭的结果说明此病一定属于常染色体隐性遗传病

  C.第Ⅲ类家庭的结果说明此病一定属于隐性遗传病

  D.第Ⅳ类家庭的结果说明此病一定属于隐性遗传病

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