问题 选择题

下列属于相对性状的是(  )

A.家兔的长毛和粗毛

B.豌豆的绿粒和皱粒

C.鸡的单冠和玫瑰冠

D.狗的白毛和猫的黑毛

答案

同种生物同一性状的不同表现形式称为相对性状.

A、家兔的长毛和粗毛,是家兔毛的长短与粗细,是两种性状,不是相对性状;如家兔的长毛与短毛,或家兔的粗毛与细毛,都是相对性状.故不符合题意;

B、豌豆的绿粒和皱粒,是豌豆粒的颜色与种皮的形状,是两种性状,不是相对性状;如豌豆的绿粒与黄粒,或豌豆的皱粒与光滑粒,都是相对性状.故不符合题意;

C、鸡的单冠和玫瑰冠,是鸡冠的形状不同,是同一性状的不同表现形式,是相对性状;故符合题意;

D、狗的白毛和猫的黑毛,是狗和猫,是两个物种,不是相对性状.如狗的白毛与黑毛,或猫的白毛与黑毛,都是相对性状.故不符合题意.

故选C.

阅读理解

     A quarrel at home may result in you falling ill. Don't laugh, it's true. Family matters including living

habits and even the way we speak have a big effect on our health, doctors say.

     Wang Xiaoyu, a Senior 2 girl from Xichang, Sichuan Province, fainted (晕倒) in class when she heard her classmates quarrel at the top of their voices. Quarrels between her parents also put the girl into a

coma. It is because she is suffering from depression (抑郁症), caused by bad relations at home, doctors

explained.

     "We don't get sick or stay well by ourselves," says Dr Robert Ferrer from the US. Ferrer shows that

family forces may explain up to a quarter of health problems, in his recent research. The genes you get

from your family may cause illness. If one of your parents has a heart attack, your risk of being affected

may double. But effects on health are not only written in our DNA.

     Unrelated people who live under the same roof also get similar problems. Diet, lifestyle and

environment affect our health, too. Ferrer's research also found that if teenagers feel they are ignored or

unimportant at home they are more likely to get sick.

     We may never fully understand all the effects that families have on our health. But just as individual

(个别的) problems can have effects on others, a small improvement can have big benefits, Ferrer said.

1. Which of the following can best explain why Wang Xiaoyu fainted in class?

A. Because her classmates often quarreled in class.

B. Because her parents used to quarrel.

C. Because of her depression caused by bad family relations.

D. Because her classmates shouted loudly at her.

2. According to Dr Ferrer, which of the following statements is TRUE?

A. We get sick or stay well by ourselves.

B. Only the genes we get from our family have a big effect on our health.

C. Our health has nothing to do with diet, lifestyle and environment.

D. Teenagers who are ignored at home get sick more easily than those who are not.

3. The underlined word "coma" in Paragraph2 probably means ________.

A. surprise    

B. faint        

C. tiredness

D. sadness

4. The best title for this passage is ________.

A. Family relations.                

B. The reasons why we get sick.

C. Family—another cause to health    

D. A research about health.

填空题