核酸分为哪两类．它们在组成上有什么差异?
正确答案及解析
正确答案
解析
核酸分为核糖核酸(RNA)和脱氧核糖核酸(DNA)两类。它们在组成上的差异如下：
①单体不同。核糖核酸的单体是核糖核苷酸；脱氧核糖核酸的单体是脱氧核糖核苷酸。
②五碳糖不同。核糖核酸的五碳糖是核糖：脱氧核糖核酸的五碳糖是脱氧核糖。
③碱基不同。核糖核酸的碱基是A、G、C、U；脱氧核糖核酸的碱基是A、G、C、T。
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