試題詳解

 1. The difference between a ribonucieotide and a deoxyribonucleotide is that a ribonucleotide has an --OH instead of an -H at C-2. 

 2. The DNA copies of mRNA found in a cDNA libtary are made by reverse transcriptase. 

 3. Type II restriction enzymes cleave DNA only at recognition sequences specific to a given restriction enzyme

 4. Deamination of the nucleotide base 5-methylcytosine yields nucleotide base thymine.

 5. Type II restriction enzymes may make staggered (off-center) cuts within their recognition scquences.
(A) 5 only
(B) 3 only
(C) 4 only
(D) 1 and 2
(E) Nonc of the descriptions are false.