题干

已知玉米有色籽粒对无色籽粒是显性.现将一有色籽粒的植株X进行测交,后代出现有色籽粒与无色籽粒的比是1:3,对这种杂交现象的推测正确的是(  )

A:测交后代的有色籽粒的基因型与植株X相同

B:玉米的有、无色籽粒遗传不遵循基因的分离定律

C:玉米的有、无色籽粒是由一对等位基因控制的

D:测交后代的无色籽粒的基因型有两种

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答案(点此获取答案解析)

A

同类题4

阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。

    Sometimes it's necessary to take a break, relax and forget the routine (日常工作), so I know of an excellent place to do it outside the city. It's a beautiful place and I really enjoy going there.

    The name is Tepoztlán, 71 km south of Mexico City. Here you can find a lot of different meals, beautiful landscapes, historical buildings, local souvenirs, and so on.

    The weather most of the time is very hot, and I have to give you some advice if you go.

● Use sun block ● Wear comfortable clothes, sunglasses and a hat ● Drink a lot of water

    I give you this advice because I ended up with sunstroke. I'm going to tell you how my trip started. When we got there we were really starving, so we decided to have breakfast and when we go to Tepoztlan we usually enjoy "quesadillas" in the market.

    In Mexico, it's very common to eat in the market, but these kinds of markets not only sell food but also you can buy clothes, flowers, everything you can imagine.

    Tepoztlan has a lot of tourist sites, but the main attraction is Tepozteco hill, and it's more attractive for the visitors during "Spring Equinox". To be honest, I've never climbed it, I'm too lazy to walk a lot and even more in the sun.

    In my trip we didn't have time to do all that because one day is not enough, but if you have the opportunity to stay for more than one day it's an excellent idea.