What is Chargaff’s ratio? () A: In any organisms, amount of Adenine is the same as Thymine, amount of Cytosine is the same as Guanine. B: In any organisms, amount of Adenine is the same as Cytosine, amount of Thymine is the same as Guanine. C: In any organisms, amount of Adenine is the same as Guanine, amount of Thymine is the same as Cytosine.

哪些核苷酸碱基存在于RNA中？ A: adenine, guanine, cytosine, thymine B: adenine, guanine, thymine C: adenine, guanine, cytosine, uracil D: sugar, phosphate and base

5-bromouracil is an analog of which base? A: thymine B: uracil C: cytosine D: adenine

If a sample of DNA extracted from a culture of cells is found to have 18% guanine, what would the expected proportion of thymine be from this culture? A: 18% B: 32% C: 36% D: 64%