Question

what was marshall nirenberg and heinrich matthaeis contribution to our current understanding of the genetic code? discovery of codons discovery and extraction of dna creation of a model of dna creation of photo 51

Explanation:

Marshall Nirenberg and Heinrich Matthaei conducted experiments that led to the discovery of codons, the triplet - nucleotide sequences in mRNA that code for specific amino acids. The discovery of DNA was earlier work, the model of DNA was created by Watson and Crick, and Photo 51 was produced by Rosalind Franklin.

Answer:

discovery of codons