【简答题】(12分)某蛋鸡羽色有黑色与麻色,由常染色体上的基因(A/a)控制,其胫色有浅色对深色为显性,由另一对同源染色体上的基因(D/d)控制。为判断基因(D/d)是否位于Z染色体(ZW型)上,用黑羽浅胫公鸡与黑羽深胫母鸡杂交,后代表现型及比例为:黑羽深胫:黑羽浅胫:麻羽浅胫:麻羽深胫=2:2:1:1。请回答下列问题: (1)子代黑羽所占的比例为2/3,出现该比例的原因可能是_______________...
【单选题】关于种群的基本特征,以下说法 不正确 的是 ( )
【多选题】下列有关说法错误的是哪一或哪些选项? ( )
A.
法律对人们的行为或者社会关系,既产生正面作用,也产生负面作用
B.
法律对人们的行为或者社会关系,只能产生积极作用,没有消极作用
【单选题】下面关于国务院与全国人民代表大会关系的说法,错误的是哪一或哪些?( )
C.
全国人大常委会有权改变或撤销国务院制定的同宪法、法律相抵触的行政法规、决定和命令
【简答题】下列各句均有一处错误,在错处下面划线,并改正。 1. Excuse me, Miss Green. Can I ask you any questions? 2. Do you think Mary have a TV? 3. Can Li Lei play the tennis? 4. The boys play football on every Monday afternoon. 5. Do...
【简答题】These days more and more people are 1.________(rent / renting) homes. There are many places where you can find a rental home. You can look on rental 2.________(websites / apartments). You can also ask...
【简答题】Complete these sentences about or from meetings with a suitable verb below. set give move hold go take run see attend reach 1. I’d like to ______ a brief meeting next week. Do you ha...
【简答题】二、选词填空5题。 without difficulty keep on confidence graduate 1. Those who _____ from famous universities can get a good job easily. 2. No smoke ____ fire. 3.As you can see, the number of cars ...