求助OG-10第180题及对于让步语气的正确理解

这道题凭着理解是可以选出正确选项的，但是在看后面解释的时候对于A选项的排除方法突然很困惑，OG解释:The passage contradicts the idea thatprokaryotes "form a coherent group"(choice A)because it states that there is "one respect" in which new evidence contradicts the hypothesis等等，我的疑问是1.让步中语气与转折二者互为取非如何理解，是否这就是The passage contradicts the idea thatprokaryotes "form a coherent group"(choice A)这句话的来源，因为文中出现这句话的地方是although的后面，即让步本身；2. 后面的这个because是怎么来的，我无论如何也没有看出来。请牛人指点迷津，不慎感激。

不是NN,只是我对这题的理解

第二段...in one aspect.

Among the bacteria, there are organisms that are

significantly different both from the cells of eukaryotes and

(30)from the true bacteria, and it now appears that there are

three stems in the tree of life. 就是说原来曾经一度认为生物界是分为两类,eukaryotic(one aspect)和prokaryotic-包括真菌(another aspect,原文是 On the other hand)

可是在新的理论里,eukaryotic不变,可是曾经一度认为prokaryotic form a coherent group的观点不再正确.

文章最后一句certain other bacteria,

the archaebacteria, which are also prokaryotes and which resemble true

(40) bacteria, represent a distinct evolutionary branch that

far antedates the common ancestor of all true bacteria.

这里容易引起糊涂.因为原来的理论是说On the

other hand, the true bacteria are prokaryotic cell, which

are simple and lack a nucleus. 这里说的是the true bacteria,而文章最后一句certain other bacteria,