B C B D B 6 - 1 0 C D A C D 1 1 - 1 5 D B B B B 1 6 - 2 0 A B B A D
2 1 . (1 )
(2 )1 ∶ 3 A a 1 × A a 2
(3 ) ∶ = 1 ∶ 5 ∶ = 1 ∶ 1
(4 ) —
2 2 . (1 ) B D ∶ B d ∶ b D ∶ b d = 1 ∶ 1 ∶ 1 ∶ 1
(2 )3 / 7
A a a
(3 )a X B b X X b b X Y
2 3 . (1 ) C 、 H 、 O 、 N 5
(2 )
(3 )e D N A ② ①
(4 )0 .7
2 4 . (1 ) R N A
(2 ) A — U
(3 ) ( m R N A )
(4 ) H R C R m i R - 2 2 3 (2 ) , ( 2 ,
) ,