练习册

  • 练习册
  • 试题
    精英家教网 > 高中地理 > 题目详情

    【题目】果蝇的红眼（R）对白眼（r）是显性，控制眼色的基因位于X染色体上。现用一对果蝇杂交，一方为红眼，另一方为白眼，杂交后F1中雄果蝇与亲本雌果蝇眼色相同，雌果蝇与亲本雄果蝇眼色相同，那么亲本果蝇的基因型为（ ）

    A．XRXR×XrY B．XrXr×XRY

    C．XRXr×XrY D．XRXr×XRY

    【答案】B

    【解析】

    XRXR×XrY→XRXr×XRY，可见子代雌、雄果蝇的性状均与亲代雌果蝇相同；XRXr×XrY→XRXr、XrXr、XRY、XrY，可见子代雌雄果蝇均有红眼和白眼性状；XrXr×XRY→XRXr×XrY，可见雄果蝇与亲代雌果蝇眼色相同，子代雌果蝇与亲代雄果蝇眼色相同；根据题干信息“双亲中一方为红眼，另一方为白眼”可知，亲本的基因型不可能为XRXr和XRY。

    练习册系列答案
    年级 高中课程 年级 初中课程
    高一 高一免费课程推荐！ 初一 初一免费课程推荐！
    高二 高二免费课程推荐！ 初二 初二免费课程推荐！
    高三 高三免费课程推荐！ 初三 初三免费课程推荐！
    相关习题

    科目：高中地理 来源： 题型：

    【题目】听一段材料，回答下面几个小题。

    【1】What does the speaker like to know about a new play?

    A. Whether it is worth seeing.

    B. The price.

    C. How long it lasts.

    【2】Why were they late for the theatre?

    A. Because they missed the bus.

    B. Because there was too much traffic on the way.

    C. Because his wife spent too much time deciding what to wear.

    【3】Where did they go after the play?

    A. To a restaurant.

    B. To a night club.

    C. To their home.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】What's the probable relationship between the two speakers?

    A. Strangers.

    B. Classmates.

    C. Workmates.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】听一段材料，回答下面几个小题。

    【1】When did Jones have to work?

    A. In 1948.

    B. In 1971.

    C. In 1979.

    【2】What did Jones study in the University of Pennsylvania?

    A. Math.

    B. Construction.

    C. Computer.

    【3】How old was Joe Jones when he completed the work on his master's degree?

    A. 48.

    B. 55.

    C. 65.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】What can be concluded about Judy?

    A. Judy came to the party.

    B. Judy planned the party.

    C. Judy hasn't appeared yet.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】How many students took the exam?

    A. Forty students.

    B. Fifty students.

    C. Twenty-five students.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】What is the man’s attitude towards the cafeteria?

    A.He doesn’t mind eating there.

    B.He doesn’t like the food there.

    C.He likes the food,but it’s crowded.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】How does the man feel about the doctor's advice?

    A. Well worth acting on.

    B. Too difficult to follow.

    C. A foolish idea.

    查看答案和解析>>

    科目：高中地理 来源： 题型：

    【题目】听一段材料，回答下面几个小题。

    【1】Where does this conversation most probably take place?

    A. In a restaurant.

    B. In a hospital.

    C. In a bank.

    【2】How does the woman respond to the service here?

    A. By complaining.

    B. By questioning.

    C. By ignoring.

    【3】What does the man promise to do?

    A. Pay back the woman's money.

    B. Make an apology to the woman.

    C. Inform someone in charge of the matter.

    查看答案和解析>>

    同步练习册答案