题干

如下图所示,将二倍体植株①和②杂交得到③,再将③作进一步处理。对此分析错误的是(     )

A:由⑤得到⑥的育种原理是基因重组

B:图中秋水仙素的作用是使染色体数目加倍

C:若③的基因型是AaBbdd,则⑨的基因型可能是aBd

D:③至④的过程中,所产生的变异都有利于生产

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答案(点此获取答案解析)

D

同类题1

阅读理解

B

    One morning a boy went home with his father. They noticed a pair of old shoes by the roadside. They thought the shoes might be a poor man's. In fact, the owner of the shoes was working in the field nearby, and he had nearly finished his work.

    The boy said to his father, "Let's play a trick on the man—we hide his shoes, and wait to see what he will do when he can't find them."

    "My boy, we should never have fun by tricking other people like that," answered his father. "Instead, let's put a coin in each of the shoes, and watch he will do."

    The boy did so, and then they hid nearby.

    The man soon back to get h is shoes, but when he put his foot into one of his shoes, he felt something in it. He bent(弯曲)down and found the coin.

    Surprise appeared on his face. He looked at the coin for a minute, and then looked around, but nobody could be seen. He then went on to put on the other shoe, but he was even more surprised to find the second coin.

    He then went down on his knees, looked up to the sky and said thanks aloud. He said his wife was ill and his children were hungry. He wanted to buy some bread for them.

    The boy was deeply moved.

    "Now," said his father, "you must be much more pleased than if you had played your trick."

    The boy replied, "You have taught me a lesson which I'll never forget. Now I understand these words, which I didn't understand before: It is more blessed(神圣的)to give than to receive."