题干

果蝇的翅有长翅和残翅两种,眼色有红眼和白眼两种,分别由A、a和B、b两对等位基因控制.甲图为某果蝇的染色体及基因组成,将该果蝇与“另一亲本”杂交,F1的表现型及其数量关系如乙图,请分析回答:

(1)甲图所示的果蝇体细胞有丝分裂后期移向两极的染色体上的基因组成分别是____ ;减数第一次分裂后期移向两极的染色体上的基因组成分别是____ ;减数第二次分裂后期移向两极的染色体上的基因组成分别是____ .

(2)分析甲、乙两图可知与该果蝇杂交的另一亲本的基因型为____ ,F1长翅红眼雌蝇中纯合体占的比例为____ .

(3)F1长翅红眼雌雄果蝇自由交配,F2中残翅白眼雌果蝇所占比例为____ ,残翅白眼雄果蝇所占比例为____ .

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同类题2

阅读下面短文,请从每小题所给的A、B、C、D四个选项中选出最佳选项,并回答问题。

C

    Once upon a time,there was a king who had gone to visit neighboring kingdoms.He was gifted a pair of baby parrots by the king of the last kingdom where he was visiting.They were the most beautiful birds that he had ever seen.so,after returning to his kingdom,he called for a bird trainer and asked him to train parrots.

    The king also set up a place in the palace garden for the parrots.He often looked at them from his palace window.As time passed,one day the trainer came to the palace and told the king that though one of the parrots was flying high in the sky,the other one was not moving from its branch since the day it had arrived.

    When hearing this,the king summoned the best trainer from all his land and the nearby kingdoms.They came quickly and tried their best, but none of them could make the parrot fly!He even asked his courtiers to try to find a good way to make the parrot fly but they all failed.The parrot was not moving from his branch at all.Finally,after trying everything,the king thought to himself:"Perhaps I need someone who may be more familiar with natural habitat."He asked his courtier to get a farmer from the countryside and take him to the parrot to see if he could understand the problem with the parrot.

    The next morning,the king was surprised to see the parrot flying high above the palace gardens.He asked his servant to call that farmer to meet him.The servant quickly went and found the farmer.The farmer came and stood before the king.The king asked him,"How did you make the parrot fly?" With his hands folded with respect,the farmer said to the king,"It was very easy.I just cut the branch where the bird was sitting."