问题 选择题

孟德尔利用“假说—演绎法”发现了遗传的两大定律。其中,在研究基因的自由组合定律时,针对发现的问题提出的假设是[     ]

A.F1表现显性性状,F1自交产生四种表现型不同的后代,比例为9:3:3:1

B.F1产生数目、种类相等的雌雄配子,且结合几率相等

C.F1形成配子时,每对遗传因子彼此分离,不同对的遗传因子自由组合,F1产生四种比例相等的配子

D.F1测交将产生四种表现型的后代,比例为1:1:1:1

答案

答案:C

改错题

第二卷   写作(共35分)

第四部分:书面表达(共两节,35分) 

第一节短文改错(共10小题;每小题1分,满分10分)

此题要求改正所给短文中的错误。对标有题号的每一行作出判断:如无错误,在该行右边横线上画一个勾(√);如有错误(每行只有一个错误),则按下列情况改正:

此行多一个词:把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。

此行缺一个词:在缺词处用一个漏字符号(^),在该行右边横线上写出该加的词。

此行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。

On March 12th, we went to plant trees on the hill near to    76.        

our school.  The boys were made dig pits(坑).The         77.       

girls were told to plant the young trees into the pits.        78.       

All of us worked very hardly. Soon we were all wet         79.         

with sweat. After the young trees planted, we               80.                 

began to water it. The water was at the foot of              81.                 

the hill.  But we stood in line to pass pails(桶)             82.                

of water from one to other up to the hill.                  83.        

We did not finish water the trees until it                   84.         

was dark. Though we were tired, we feel very happy.        85         

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