In the genetic code dictionary , how many codons are used to code for all the 20 essential amino acids? [Should we count the stop codon or not as they don't code for any amino acid]

(a)20 

(b)64 

(c)61

(d)60

Asked by Balbir | 5th Jan, 2020, 07:35: PM

Expert Answer:

  • Out of 64 codons three codons (UAA, UAG, UGA) are chain terminating codons or stop codons.
  • The translating mechanism is not able to read these codons. Hence, they do not code for any amino acid.
  • 61 codons are used to code all the 20 essential amino acids.  
  • So, the correct answer is option (c) 61.

Answered by Sheetal Kolte | 7th Jan, 2020, 11:21: AM

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