OG－25题，请教

晓晓

OG的第五篇文章，是关于动物细胞在胚胎期的发展

25、 It can be inferred from the passage that the mophorgenetic determinants present in tne early embroy are

...
C  inactive until the embroy cell become irreversibly committed to their final function
...
E  present in large quntities than is necessary for the development of a single individual

看了OG的解释后，对正确选项E可以理解，但是原文中也有这么一段话：In the unfertilized egg, the substances are inactive and not distributed homogeneously.那么为什么排除C呢？OG 对C 选项的解释仅限于directly contracted by information from the passage ，对此无法理解
请帮忙解释一下，谢谢！   

qww

答案C 的问题出在时间的修饰上。inactive until the embroy cell become irreversibly committed to their final function 。
until the embroy cell become irreversibly committed to their final function是不对的。when the egg is fertilized,the substances become active and,。。。。
不是胚胎发育到不能改变命运的地步，而是刚有胚胎就已经 active。

晓晓

oh, I see!!!

thanks so much!

xionghuixh

i want to ask a special question about whether embryo is fertilized?

xionghuixh

我想胚胎早期应该处于已经受精,正在合成histones 得时候.

不知我的理解对不??

wangyu73cn

http://forum.chasedream.com/dispbbs.asp?boardID=25&ID=77989&page=1

不太明白xionghuixh所指，不管如何，请参照以上链接，或许能对理解此题有所帮助。。

drift_er

考试时碰到这种题，做好的办法就是放弃。

swlfx

有道理.