本题目来源于试卷: Unity and Diversity A.8 Evolution and Speciation，类别为 IB生物学
[单选题]
The base sequence between 9nmrq4 9-4vp+uhrc ihtwo specic6/i(*qlkq jz es was found to be 78% the same, while the ork(6qql/ ci *jzder of amino acids found in the same cell types between two species was 82% the same. What may be the reason for this?
A. The genetic code is degenerate.
B. Mutations occur more frequently in DNA that codes for proteins.
C. Techniques used to analyse base sequences of DNA are less reliable.
D. The genetic code is universal.
参考答案: A
本题详细解析:
Choice A is correct because what is meant by “the genetic code is degenerate” is multiple codons sometimes code for the same amino acid, which means that sometimes a mutation will change the genetic code, but the same amino acid is still coded for. Choice B is incorrect as mutations generally occur more frequently in DNA that does not code for proteins. Choice C is incorrect as techniques used to analyse the base sequence of DNA are more reliable than those used to determine the order of amino acids. Choice D is incorrect as the universality of the genetic code refers to the fact that all organisms use the same genetic code.
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