问题 判断题

一对双眼皮的父母,不可能生一个单眼皮的孩子。          (    )

答案

题目分析:双眼皮是显性性状,单眼皮是隐性性状,B表示控制双眼皮的显性基因,用b表示控制单眼皮的隐性基因,一对双眼皮的父母其基因组成是BB或Bb.如果是基因组成BB,他们的孩子一定是双眼皮,没有单眼皮的孩子,如果是基因组成为Bb,那么子女的基因有:BB、Bb、bb,因此一对双眼皮的父母,有可能生一个单眼皮的孩子。

点评:此题为基础题,解答此题的关键是掌握并理解基因的显性和隐性以及它们与性状表现之间的关系,可结合遗传图解进行解题。

阅读理解

I needed to buy a digital camera, one that was simply good at taking good snaps (快照), maybe occasionally for magazines. Being the cautious type, I fancied a reliable brand. So I went on the net, spent 15 minutes reading product reviews on good websites, wrote down the names of three top recommendations and headed for my nearest big friendly camera store. There in the cupboard was one of the cameras on my list. And it was on special offer. Oh joy. I pointed at it and asked an assistant, “Can I have one of those?” He looked perturbed (不安).“Do you want to try it first?" he said. It didn't quite sound like a question. "Do I need to?" I replied. "There's nothing wrong with it?" This made him look a bit insulted and I started to feel bad. "No, no. But you should try it," he said encouragingly." Compare it with the others. "

I looked across at the others: shelves of similar cameras placed along the wall, offering a wide range of slightly different prices and discounts, with each company selling a range of models based around the same basic box. With so many models to choose from, it seemed that I would have to spend hours weighing X against Y, always trying to take Z and possibly H into account at the same time. But when I had finished, I would still have only the same two certainties that I had entered the store with: first, soon after I carried my new camera out of the shop, it would be worth half what I paid for it; and second, my wonderful camera would very quickly be replaced by a new model.

But something in the human soul whispers that you can beat these traps by making the right choice, the clever choice, the wise choice. In the end, I agreed to try the model I had chosen. The assistant seemed a sincere man. So I let him take out my chosen camera from the cupboard, show how it took excellent pictures of my fellow shoppers... and when he started to introduce the special features, I interrupted to ask whether I needed to buy a carry-case and a memory card as well.

Why do we think that new options (选择) still offer us anything new? Perhaps it is because they offer an opportunity to avoid facing the fact that our real choices in this culture are far more limited than we would like to imagine.

1. The shop assistant insisted that the writer should __ .

A. try the camera to see if there was anything wrong with it

B. compare the camera he had chosen with the others

C. get more information about different companies

D. trust him and stop asking questions

2. What does the writer mean by "it would be worth half what I paid for it"  (Paragraph 2) ?

A. He should get a 50% discount.

B. The price of the camera was unreasonably high.

C. The quality of the camera was not good.

D. The camera would soon fall in value.

3. The writer decided to try the model he had chosen because he __ .

A. knew very little about it

B. didn't trust the shop assistant

C. wanted to make sure the one he chose would be the best

D. had a special interest in taking pictures of his fellow shoppers

4. It can be inferred from the passage that in the writer's opinion, __

A. people waste too much money on cameras

B. cameras have become an important part of our daily life

C. we don't actually need so many choices when buying a product

D. famous companies care more about profit than quality

多项选择题