A:选用T2噬菌体作为实验材料的原因之一是其仅由蛋白质外壳和DNA组成
B:标记噬菌体的方法是分别用含32P和35S的培养基培养噬菌体
C:噬菌体DNA在细菌体内复制利用的原料是自身的脱氧核苷酸
D:若噬菌体DNA复制了三次,则含有35S的子代噬菌体占总数的1/2
下列描述中,属于遗传现象的是( )
小张买一张入场券,它的号码是四位数,其中个位上的数是质数,十位上的数是5的倍数,百位上的数是偶数,千位上的数是个位上的数的3倍。入场券的号码是( )。
Zhang Lin is a middle school student. He is a good boy. Uncle Wu lives next to him. Uncle Wu has no child and can't see anything. He works in the factory (工厂) near Zhang Lin's school. He goes to work at 7:30 in the morning and comes home at 4:30 in the afternoon. Zhang Lin walks to school at 8:00 in the morning and comes home at the same time as Uncle Wu in the afternoon. On weekdays Zhang Lin gets up early to take Uncle Wu to the factory. After school he takes him home. On Sundays Zhang Lin helps Uncle Wu clean the house and do some cooking. Uncle Wu thanks Zhang Lin very much. He says, “Zhang Lin is a good boy. He is like my son.”