题干

遗传规律

果蝇的变异类型较丰富,已发现其眼色(A、a)、体色(E、e)、肢形(T、t)、后胸形态(F、f)的四类性状由X、二号、三号染色体上的等位基因所控制.

为了解控制这些性状基因的关系,研究人员做如下实验与结果记录:

组别

亲本

子一代表型与比例

一组

白眼♀×红眼♂

红眼♀♂白眼

1:1

二组

红眼灰体色♀×白眼灰体色♂

红眼灰体色♀红眼黑体色♀红眼灰体色♂红眼黑体色♂

3:1:3:1

三组

异常胸♀×正常胸♂

正常胸♀正常胸♂

1:1

四组

正常胸长肢♀×异常胸短肢♂

正常胸长肢♀正常胸长肢♂异常胸长肢♀异常胸长肢♂

1:1:1:1

五组

灰体色长肢♀×黑体色短肢♂

灰体色长肢♀灰体色长肢♂黑体色长肢♀黑体色长肢♂

4:4:1:1

灰体色短肢♀灰体色短肢♂黑体色短肢♀黑体色短肢♂

1:1:4:4

综合四组实验,回答:

(1)写出第一组双亲的基因型:____ 

(2)写出第二组母本的基因型:____ 

(3)若体色基因位于三号染色体上,则后胸形态的基因位于____ 号染色体上.

(4)写出第五组亲本的基因型:____ ;第五组子一代灰体色长肢的雌果蝇与黑体色长肢雄果蝇交配,所生后代果蝇中,灰体色果蝇出现的几率是____ ;黑体色长肢纯合体果蝇出现的几率是____ .

上一题 下一题 0.0难度 选择题 更新时间:2011-06-03 01:07:40

答案(点此获取答案解析)

XaXa、XAY,EeXAXA,二,ET∥et,
1
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