When decoding the lilac genome, it was found that the fraction of nucleotides with cytosine in a fragment of a DNA molecule is 30%. Using Chargaff’s rule, which describes the quantitative ratios between different types of nitrogenous bases in DNA (G + T = A + C), calculate the amount (in%) in this sample of nucleotides with adenine.
Adenine (A) is complementary to thymine (T), and guanine (G) is complementary to cytosine (C), therefore the number of complementary nucleotides is the same; Chargaff’s rule: (A + T) + (G + C) = 100%
By condition C = 30%
A + T = 100% – (30% + 30%) = 40%
A = T = 40%: 2 = 20%
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.