问题 选择题

人的耳垢有油性和干性两种,是受单基因(A、a)控制的。有人对某一社区的家庭进行了调查,结果如下表:

下列分析错误的是[ ]

A.控制该相对性状的基因位于常染色体上

B.一对油耳夫妇生了一个干耳儿子,推测母亲的基因型是Aa

C.从第一组的数据看,子代性状没有呈现3:1的性状分离比,其原因是第一组的双亲基因型可能为AA或Aa

D.若一对于耳夫妇生了一个左耳是干性的、右耳是油性的男孩,出现这种情况的原因可能是生殖细胞突变

答案

答案:D

单项选择题
阅读理解

SANTO DOMINGO, Domincan Republic ---An infant girl born with a second head bled to death Saturday after complex surgery (外科手术) to remove her partially formed twin , her parents and doctors said.

A medical team completed the 11- hour operation Friday night and said 8-week-old Rebecca Martinez died seven hours later. Doctors had warned after the surgery that the girl would be at great risk of death.

“ We knew this was a very risky surgery , and now we accept what God has decided , “ Rebecca’s father , 29-year-old Frankin Martinez, said at a news conference with his wife. “ Rebecca is no longer with us physically , but no one will forget her.”

Martinez said the family would bury Rebecca in a private funeral later in the day.

The girl lost a lot of blood in the operation, which apparently ( 明显地) caused her to suffer a heart attack , said Dr. Jorge Lazareff , the lead surgeon . Friends and family donated (捐赠) almost 4 gallons of blood for surgeons to use Rebeca’s operation

“This was not a failure or an error ,” Lazareff said . “ When we left here last night the girl was in stable condition. At some point in the middle of the night , she started to bleed.”

Rebecca was born Dec. 10 with the undeveloped head of her twin, an exteremely rare condition known as craniopagus parasticus . Rebecca was the eighth documented case in the world of craniopagus parasiticus, doctors said.

All the other infants documented to have had the condition died before birth , making Rebecca\s surgery the first known operation of its kind.

Without an operation , Rebecca would have barely been able to lift her head at 3 months old. Her doctors said the pressure from the second head would have prevented her brain from developing.

“ We always saw Rebecca without the extra part of her body, ”er father said after her death.

Rebecca was their third child-----along with a 4-year-old boy and a 1-year-old girl.

小题1:The underlined word “infant “ most probably means____________________.

A.a disabled child

B.a newly-born child

C.a 2-headed child

D.a very young child小题2: Rebecca Martinez died ________________________after she went to the operation table.

A.8 weeks

B.11 hours

C.7 hours

D.18 hours小题3: Which of the following statements is NOT true according to the text?

A.Rebecca died because mistakes happened during the operation

B.Rebecca most probably died of bleeding

C.Rebecca was her parents’ third child

D.Without an operation , Rebecca would have little hope of living小题4: Which of the following would be the best title of the passage?

A.Infant Girl Dies After 2nd Head Removed

B.Rebecca , Hiciano’s Third Child

C.The Death of a Gril With two Heads

D.Rebecca’s Surgery, the First Known Operation