Question

[5] 1. How many different 42-nucleotide DNA molecules could give rise to the T-enzyme fragmentation AGT, AGCT, AT, AT, GGT, AGACAT, CACG, AT, AGCT, T, T, AAGAT, AGGCT Solve this problem as a product of combinations. Count in three different ways, and resolve your answer in each case to show that the counts are equivalent. How many different ways are there to count this problem using a product of combinations?

Answer 1

Answer:

​Different nucleotide combinations code for the same amino acid Some of the amino acids can be coded by more than one but specific triplet nucleotide combinations. This unique feature of triplet codons is referred to as degeneracy. For example, an amino acid Arginine can be represented by any one of the triplet codon among the following 6 nucleotide combinations : CGU, CGC, CGA, CGG, AGA, AGG. ​

All other amino acids except methionine and tryptophan ( represented by only single codon sequence) exhibot degeneracy of genetic code. Start codon (AUG) is represented by a single nucleotide combination whereas stop codon ( UAA, UGA,UAG) can be encoded by any of the 3 triplet codons.