单选题 We all know that DNA has the ability to identify individuals but, because it is inherited, there are also regions of the DNA strand which can relate an individual to his or her family (immediate and extended), tribal group and even an entire population. Molecular Genealogy (宗谱学) can use this unique identification provided by the genetic markers to link people together into family trees. Pedigrees (家谱) based on such genetic markers can mean a breakthrough for family trees where information is incomplete or missing due to adoption, illegitimacy or lack of records. There are many communities and populations which have lost precious records due to tragic events such as the fire in the Irish courts during Civil War in 1921 or American slaves for whom many records were never kept in the first place.
The main objective of the Molecular Genealogy Research Group is to build a database containing over 100,000 DNA samples from individuals all over the world. These individuals will have provided a pedigree chart of at least four generations and a small blood sample. Once the database has enough samples to represent the world genetic make-up, it will eventually help in solving many issues regarding genealogies that could not be done by relying only on traditional written records. Theoretically, any individual will someday be able to trace his or her family origins through this database.
In the meantime, as the database is being created, molecular genealogy can already verify possible or suspected relationships between individuals. “For example, if two men sharing the same last name believe that they are related, but no written record proves this relationship, we can verify this possibility by collecting a sample of DNA from both and looking for common markers (in this case we can look primarily at the Y chromosome(染色体)),” explains Ugo A．Perego, a member of the BYU Molecular Genealogy research team.．

单选题 People in a large area may possess the same DNA thread because______.

A. DNA is characteristic of a region
B. they are beyond doubt of common ancestry
C. DNA strand has the ability to identify individuals
D. their unique identification can be provided via DNA

【正确答案】 B

【答案解析】单句理解推断题题干是对第一句中“there are also regions of the DNA strand(也有一些区域具有同样的DNA线索)”的提问，原因就是前面提到的“because it is inherited(DNA具有遗传性)”，既然是遗传，那么可以推断出具有同样DNA特征的人必定有同样的祖先。比较四个选项， [B]符合这样的意思。

单选题 The possible research of family trees is based on the fact that______.

A. genetics has achieved a breakthrough
B. genetic information contained in DNA can be revealed now
C. each individual carries a unique record of who he is and how he is related to others
D. we can use DNA to prove how distant an individual is to a family, a group or a population

【正确答案】 C

【答案解析】语义理解推断题基于第一段第二、三句，我们知道遗传标记提供独有的识别特征 (unique identification)把人们连接在一起，形成家族树。换句话说，能对家族树进行研究，是因为遗传标记的独有特征可以用来判断一个人的基因身份以及与他人之间的关系，[C]项正确。[A]“遗传学取得突破”和[B]“包含在DNA中的基因信息现在可以揭示出来”没有回答进行家族树研究依据什么基础这样的问题；而[D]项强调“用DNA证明……有多远(how distant)”与文章相悖。

单选题 The Molecular Genealogy Research Group is building a database for the purpose of______

A. offering assistance in working out genealogy-related problems
B. solving many issues without relying on traditional written records
C. providing a pedigree chart of at least four generations in the world
D. confirming the assumption that all individuals are of the same origin

【正确答案】 A

【答案解析】细节理解题题干问的是建数据库的目的，对照第二段中“help in solving many issues regarding genealogies that could not be done by relying only… (有助于解决仅靠……不能解决的宗谱有关的许多问题)”。四个选项：[A]“解决宗谱有关的问题时提供帮助”，正确；[B]“无须依赖传统文字资料解决许多问题”;[C]“提供代表世界基因构成的家谱树”；[D]“获得10万份世界各地个人 DNA样本”均不正确。

单选题 If two men suspected for some reason they have a common ancestor, ______.

A. we can decide according to their family tree
B. we can find the truth from their genetic markers
C. we can compare the differences in their Y chromosome
D. we can look for written records to prove their relationship

【正确答案】 B

【答案解析】细节推断题题干的表述相当于第三段第二句的“if two men sharing the same last name believe that they are related”，做题依据是本句的后半句"we can verify this possibility by collecting a sample of DNA from both and looking for common markers"(通过采集两个人的DNA样本寻找共同的遗传标记来确定这种可能性)，[B]项符合。[C]“比较他们Y染色体的不同”，并非要强调不同，错误。

单选题 Which of the following CANNOT be inferred from the passage?

A. We are a walking, living, breathing record of our ancestors.
B. Many American slaves did not know who their ancestors were.
C. An adopted child generally lacks enough information to prove his identity.
D. Molecular genealogy can be used to prove a relationship between individuals.

【正确答案】 C

【答案解析】篇章推断题 [A]“我们的方方面面记录着我们的祖先”，可以推断，因为DNA具有遗传特性；[B]“许多美国黑奴不知道他们的祖先”，正确，依据是第一段最后一句；[C]“收养的孩子或者孤儿与他们的家族树没有关系”，不正确，因为他们与家族树的关系是基因特征而不是其他因素决定的；[D]“宗谱学能用来证明人与人之间的关系”，识别和证明人的身份关系是宗谱学的目的，正确。