问题 单项选择题 A1/A2型题

在多基因遗传病中,了解遗传度最有效的方法是()

A.家系研究

B.双生子研究

C.寄养子研究

D.精神疾病的流行病学调查研究

E.环境因素的研究

答案

参考答案:B

解析:在病因学研究中,一旦证明某种疾病有家族聚集现象,下一步的工作就是找出遗传度,然后是遗传方式,最后找到基因所在的位置及功能。了解遗传度最有效的办法是双生子研究,如果疾病与遗传有关,那么同卵双生子的同病率应高于异卵双生子,通过比较同卵双生子和异卵双生子的同病率,即可算出遗传度。

阅读理解

Katie always felt there had to be something more to life than just partying, buying clothes and driving a cool car. She finally discovered what she was missing out on when she traveled halfway around the world to help poor kids.

When she was 14, she discovered a club at school called Operation Smile, an organization that supports free operation for facially deformed kids in developing countries. At that time, she joined Operation Smile just to satisfy her school's community service requirement.

After working with Operation Smile for a while, she learned different countries have different deformities (畸形). The more she learned about what affects kids around the world, the more she wanted to go abroad with Operation Smile.

At 15, she was chosen to go abroad. She was so happy – even though she didn't realize what she was getting herself into. Before her trip, she attended a weekend "mission training". That's when she was told she'd be going to the Philippines. Although she was excited, one night during training, she broke down in tears. She didn't know if she was prepared to see all these unfortunate kids. She was put to work three days after her arrival in the Philippines. Her first day was at the hospital, where she met those kids waiting for operation, and they were running around and happy, it seemed normal. Her job was to play with the kids before their operation to help them feel more at ease. She also went to nearby schools to hand out toothbrushes and teach students how to brush their teeth.

When their operation was over, the kids were always overjoyed, but their parents were blown away. Sometimes they couldn't even recognize their kids because their appearances had improved so much. They'd cry and hug the doctors and nurses and give them presents--they were so grateful.

小题1:Why did the author join the Operation Smile?

A.To help poor kids in developing countries,

B.To satisfy her own curiosity.

C.To do what was required by the school.

D.To operate on those unfortunate kids.小题2:According to the passage, Operation Smile ____.

A.is a club popular with students

B.is an organization founded by students

C.helps those unfortunate kids learn how to smile

D.offers operation for those unfortunate kids free of charge小题3:Why did the author play with those kids in hospital?

A.To make them happy.

B.To learn more shout them.

C.To teach them how to brush their teeth.

D.To make them feel relaxed about the operation.小题4:After the operation, parents felt surprised for their kids' had improved so much.

A.health condition

B.looks

C.smile

D.mood

判断题