问题 读图填空题

根据要求回答基因与染色体、遗传规律、伴性遗传等方面的问题:

(1)某试验动物正常体细胞中有28条染色体,雌雄异体。下图是科学家对其一条染色体上部分基因的测序结果,请据图回答问题:

①.图中黑毛与长毛两个基因是否为等位基因?__________。

②.欲测定该试验动物基因组的核苷酸序列,应测定________条染色体中的DNA分子。

(2)假设该试验动物鼻的高矮受一对等位基因控制,基因型BB为高鼻,Bb为中鼻,bb为矮鼻。长耳与短耳受另一对等位基因控制(用C、c表示),只要有一个C基因就表现为长耳。这两对等位基因的遗传遵循自由组合定律。现有高鼻短耳与矮鼻长耳两个纯种品系杂交产生F1,F1自交得F2。则F2的表现型有________种,其中高鼻长耳个体的基因型为________,占F2的比例为________。

(3)若该试验动物黑毛与白毛由两对同源染色体上的两对等位基因(A1与a1,A2与a2)控制,且含显性基因越多颜色越深。现有黑毛与白毛两个纯系杂交得F1,F1自交得F2,F2中出现了黑毛、黑灰毛、灰毛、灰白毛、白毛五个品系。F2中,五个品系的个体比例是_________________________。

(4)该试验动物属于XY型性别决定。D、d基因位于X染色体上,d是隐性可致死基因(导致隐性的受精卵不能发育,但Xd的配子有活性)。能否选择出雌雄个体杂交。使后代只有雌性?________。请根据亲代和子代基因型情况说明理由___________________。

答案

(1)①.不是     ②.15

(2)6     BBCC、BBCc        3/16

(3)1:4:6:4:1

(4)不能      该试验动物中,雄性只有XD个体,雌性有XDXd和XDXD的个体。雌雄个体的两种杂交组合中均会出现XDY的雄性个体(其它答案合理也可)

阅读理解

阅读理解。

     Basketball is a young game.  In the year of 1891, a famous college was having some trouble with its

boy students.  The weather was bad. They couldn't play outside. So they were unhappy.  Sometimes

they even got into fights.

    Finally, some teachers asked Dr Naisimth to invent a game so that the students might have something

to play indoors.

    Dr Naisimth thought for a few days and invented a kind of ball game.  It was a fast, exciting game with much moving and passing of the ball. It was played between two teams.  In order to make a score, the

ball had to be thrown into a basket ten feet above the floor on the wall.

    At first, Dr Naisimth had planned to have the ball thrown into a box.  As' he couldn't find boxes of the

right size,  he had to use fruit basket instead.  That is how the game got its name basketball. The history

of this game is over 100 years.   

根据短文内容,选择正确的答案。

1. Basketball is _____ game.

A. a difficult    

B. an easy    

C. a young

2. Who invented the basketball game?

A. Dr Brown.    

B. Dr Naisimth.    

C. Mr Black.

3. Basketball was invented for the students   ___ in bad weather.    

A. to play happily indoors

B. to play outside

C. to fight indoors

4. Basketball game was played        _.    

A. between two teams  

B. among three teams    

C. by a team

5. Basketball has its history of  __   years now.

A.10    

B. more than 100    

C. less than 100

多项选择题