Question

State whether the following statement is true or false.

In 1964, Marshall Nirenberg broke the genetic code by showing that UUU is the mRNA codon for the amino acid glycine.

Answer 1

This statement is false.

Explanation:

While Marshall Nirenberg (along with Heinrich Matthaei) did break the genetic code in the early 1960s, he discovered that the codon UUU codes for the amino acid phenylalanine, not glycine. This landmark “poly-U” experiment was the first time a specific nucleotide sequence was matched to a specific amino acid, eventually earning Nirenberg a Nobel Prize. The codon for glycine is actually GGG, GGA, GGU, or GGC.