27. - Why didn’t you pay the accommodation rent?
-The rent? .
A. It all depends. B. It’s up to you . C. You are crazy . D. That isn’t due yet
26. - the accident happened? - It’s said to happen on his way to work
A. Do you know it is where that B. where is it that do you know
C. Do you know where it is that D. where do you know it is that
25. - Can we get everything ready by the weekend?
- It all depends on we can get Mr Green’s cooperation.
A. that B. what C. whether D. if
24. Where were you at lunch time? I a seat for you in the dining hall.
A. saved. B. was saving . C. have saved. D. had saved.
23. Stop making so much noise my neighbour will start complaining.
A. or else. B. but still . C. and then. . D. so that .
22.We’ve been looking for cheap houses but haven’ t found we like yet .
A. one B. other C. it D. that
第一节单项填空(共15小题;每小题1分,满分15分)
21.In china, pressure of passing exams tends to cause lack of students’ creativity.
A./ ; / B. the ; the C. the ; / D. / ; the
36.(15分)果蝇是遗传学研究的好材料,人们对果蝇的遗传及变异作了较充分的研究。
I.人们研究发现,Y染色体含有几十个基因。如果果蝇的刚毛、截毛这对相对性状由X、Y染色体上的一对等位基因控制,刚毛基因B对截毛基因b为显性。让刚毛果蝇与截毛果蝇杂交,后代中,雌果蝇全为刚毛,雄果蝇全为截毛,则亲本的杂交组合为(基因型): 。用遗传学图解表示这一杂交过程。
遗传学图解:
II.某生物兴趣小组饲养了一批纯合的长翅红眼果蝇幼虫,分装在10支试管中,准备放在25℃培养箱中培养(果蝇生长的最适温度),由于疏忽,其中有2支试管未放入培养箱,当时气温高达37℃,十天后观察发现,培养箱中的果蝇全为长翘,而未放人培养箱中的果蝇出现残翅。
(1)果蝇细胞中基因的载体有 你认为基因、环境因素、性状三者关系是怎样的?
(2)残翅性状的出现在遗传学上称为 。你认为出现残翅的可能的原因有①
②
(3)请设计实验证明你的推测。(简要写出实验步骤,预期结果并得出结论。提示:选择果蝇杂交的方法进行实验)
实验步骤:a.
b.
c.
预期结果与结论:
①: ;
②: 。
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