本题目来源于试卷: Unity and Diversity A.2 Nucleic Acids，类别为 IB生物学
[单选题]
Statements below show three double-stranded nucleotide s)vt8lk. mrs 7p+bl 4rrequko 5l+ay;,o izences. Which of these sequences of base pairs is possible in a ,+ozy 5l oi;akDNA molecule?
I. 5’- GGA CAG AGC -3’
3’- CCT GTC TCG -5’
II. 5’- GGA CAG AGC -3’
3’- TTC ACT CTA -5’
III. 5’- AGG GAC CGA -3’
3’- TCC CTG GCT -5’
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
参考答案: B
本题详细解析:
DNA molecules consist of four nitrogenous bases:i7o:.0c3qxfp*z q:. iqo qtrf adenine (A), cytosine (C), guanine (G) and t:o* q zf0iip tcf:xqo7. r3q.qhymine (T). In DNA molecules, adenine always pairs with thymine and cytosine always pairs with guanine. This is known as complementary base pairing.Sequences I and III both follow base-pairing rules correctly. Statement II is incorrect because it shows T paired with G and A paired with C.
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