计算：T7噬菌体DNA，其双螺旋链的相对分子质量为2.5×10¬7。计算DNA链的长度（设核苷酸的平均相对分子质量为650）。

[问答题] 计算下列各题：（1）T7噬菌体DNA，其双螺旋链的相对分子质量为2.5×10-7。计算DNA链的长度（设核苷酸的平均相对分子质量为650）。（2）相对分子质量为130×106的病毒DNA分子，每微米的质量是多少？（3）编码88个核苷酸的tRNA的基因有多长？（4）编码细胞色素C（104个氨基酸）的基因有多长（不考虑起始和终止序列）？（5）编码相对分子质量为9.6万的蛋白质的mRNA，相对分子质量为多少（设每个氨基酸的平均相对分子量为120）？

[问答题] 计算题：计算分子量为3×107的双螺旋DNA分子的长度，含有多少螺旋（按一对脱氧核苷酸的平均分子量为618计算）？

[判断题] 噬菌体T7启动子，可被大肠杆菌RNA聚合酶识别也可被T7RNA聚合酶识别。A . 正确B . 错误

[问答题] 如何区分相对分子质量相同的单链DNA与单链RNA？

[单选题]相对分子质量的计算方法是（）A . （40+16+1）×2B . 40+（16+1）×2C . 40+16+1×2D . 40×（16+1）×2

11．今有以下四种蛋白质的混合物：（A）相对分子质量 12000，pI 10；（B）相对分子质量 62000，pI 4；（C）相对分子质量 28000，pI 7

[主观题](T7)A．POSITIVEB．BEHINDC．RESULT A.AFRAID THEIR COUNTRIES WILL BE LEFT(T7)______B．WHAT WAS LESS VISIBLE THEN, HOWEVER, WERE THE NEW,(T8)______FORCESC．AS A(T9)______ A GREAT DEAL OF ATTENTION IS BEING PAID TODAY TO THE SO-CALLED DIGITAL DIVIDE—THE DIVIS

[主观题](T7)A．WARNB．AWAYC．OUT A.MEN AND ANIMALS MIGHT SOON DIE(T7)______B．THEIR HANDS WERE BURNT(T8)______C．FEAR WOULD NOT(T9)______IT TO KEEP AWAY FROM THE FIRE FEAR AND ITS COMPANION PAIN ARE TWO OF THE MOST USEFUL THINGS THAT MEN AND ANIMALS POSSESS, IF T

[主观题](T7)A．DEFENDINGB．UPC．COPE A.KEEP LIVING(T7)______TO THAT IMAGEB．IF YOU CAN(T8)______WITH THREE DAYS RUNNINGC．WAYS OF(T9)______AN IDEA WHAT YOU DESCRIBE IS A HABIT OF LYING THAT IS MORE SERIOUS THAN THIS.I SUSPECT THAT THELIES YOU TELL ARE(T10)______Y

[主观题](T7)A．CHANGINGB．ALLOWED ONTOC．BROKERS A.WOMEN SHOULD BE(T7)______THE NEW TRADING FLOORB．WERE NOT(T8)______OR JOBBERSC．THE WORLD IS(T9)______DAY BY DAY THE LONDON STOCK EXCHANGE HAS BEEN FAMOUS AS A PLACE FOR MEN ONLY, AND WOMENUSED TO BE STRICTLY FOR