Nora is an American girl. She studies in a middle school. She has a little sister. Her name is Kate. Kate is only four. Nora likes Kate very much. 
Today is Sunday. Nora wants her pen. She takes out her pencil box. “ Oh , dear! Where’s my pen?” She can’t find her pen. She goes to ask her sister in her bedroom.
“Kate! I can’t find my pen. Can you see……Oh, what are you doing with (用) my pen?”
“I’m writing to my friend, Betty.” Kate answers. “But how can you? You don’t know what to write.”
“It doesn’t matter (没关系). Betty can’t read.” Kate says.

如图是果蝇体细胞中染色体组成的示意图，其中Ⅱ、Ⅲ、Ⅳ、X、Y是染色体编号，A、a、B、B、D指染色体上的基因．请据图回答：

（1）Ⅱ、Ⅲ、Ⅳ与性别决定无关，属于____ 染色体．

（2）请写出图中的同源染色体____ （用图中染色体编号填写，写完整给分）．

（3）若只考虑A、a的遗传，则遵循____ 定律．

（4）如果只考虑常染色体上的基因遗传，该果蝇与具有双隐性性状的果蝇测交，则子代中表现型为双隐性类型的果蝇占____ ．

（5）红眼（D）对白眼（d）显性，该果蝇与白眼果蝇杂交，在后代雄果蝇中白眼的占____ ．

用简便方法计算

104×25=____