问题 单项选择题

一种(2n=20)植株与一种有亲缘关系的植株(2n=22)杂交,F1加倍,产生了一个双二倍体,该个体的染色体数目为()

A.42

B.21

C.84

D.68

答案

参考答案:A

认真读图,然后回答问题:

(1)图一反映了中国近代史上的哪次战争?这次战争中国战败的主要原因是什么?(至少说出2点)                                                                                                                                                                                                                                                                                                                          (2)图二反映了中国近代史上的哪次战争?这次战争中国战胜的主要原因是什么?(至少说出2点)                                                                                                                                                                                                                                                                                                                           (3)对比上述图片,你有哪些感想?(至少3点)                                                                                                                                                                                                                                                                                                                           

选择题