根据图回答问题：

(1)图中正在进行的过程从生物学角度来看是                过程。
(2)碱基①②③分别为                ，碱基④⑤⑥分别为     。
(3)图中②和⑤，③和⑥构成的核苷酸是否相同?说明理由。                                                                                                                                                                                                                                                                                                                                  
(4)图示过程进行的场所是细胞的            内，该过程的进行除图中的内容外还需要的条件有                                                                                                       。