家猫体色由X染色体上一对等位基因 B、b控制,只含基因B的个体为黑猫,只含基因b的个体

题型:单项选择题

问题:

家猫体色由X染色体上一对等位基因B、b控制,只含基因B的个体为黑猫,只含基因b的个体为黄猫,其他个体为玳瑁猫。下列说法正确的是()

A.玳瑁猫互交的后代中有25%的雄性黄猫

B.玳瑁猫与黄猫杂交后代中玳瑁猫占50%

C.为持续高效地繁育玳瑁猫,应逐代淘汰其他体色的猫

D.只有用黑猫和黄猫杂交,才能获得最大比例的玳瑁猫

考点:高中生物基因的分离定律基因的分离定律题库
题型:单项选择题

下列不属于天体的是

A.人类的家园——地球

B.天空中飘动的云朵

C.轮廓模糊的星云

D.正在太空运行的宇宙飞船

题型:单项选择题

用所给词的正确形式填空.

1. I have two ______ (dictionary). One is English-Chinese dictionary, and the other is

    Chinese-English dictionary.

2. A: What's the result of the race, Mary?

    B: Jane is the ______ (one) in the race, Barbara is the ______ (two) and I am the ______ (three).

3. The Yellow River is the second ______ (long) river in China.

4. The boy is old enough to ______ (dress) himself.

5. The weather in Beijing is quite ______ (difference) from that in Guangzhou.

6. I'm very ______ (interest) in that ______ (interest) story.

7. It's more ______ (convenience) to take a taxi to the station than take a bus, but too expensive.

8. Be careful! Put the secret letter in a ______ (safety) place.

9. Lucy is ______ (jealousy) of her friend's beauty.

10. Liu Xiang and Yang Liwei are ______ (hero) in different fields.

题型:单项选择题

下列属于WAIS-RC言语测验的分测验是()。

A.知识

B.数字广度

C.领悟

D.数字符号

题型:单项选择题

大象的质量是4000kg,在水平地面上铺一张方格纸,大象站在纸上时留下的脚印如图所示.图中每个小方格的面积为25cm2(数方格数时,超过半个的算一格,不足半格的忽略不计).计算每只脚底的面积     m2,大象四脚站立时对地面压强是       Pa.(g=10N/kg)

题型:单项选择题

传染病流行过程的定义是()

A.各种传染源不断向外界排出病原体

B.病原体侵袭易感者

C.病原体在中间宿主中的传代

D.病原体通过一定的传播途径,不断更迭其宿主的过程

E.病原体在宿主体内生长、繁殖的过程

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