What did Marshall Nirenberg and Heinrich Matthaei discover?

Answer 1

Marshall Nirenberg and Heinrich Matthaei discovered and understood the genetic code through a series of experiments. These include the famous Poly-U-Experiment, which Heinrich Matthaei undertook alone on May 27th, 1961.

Answer 2

okay so basically it started like this....

Nirenberg and Mattaei ran a series of experiments to see what amino acids in particular necleotide template gave rise to. Strands of template with a known combination of necleotidea were run through the "cell free" system. They made a very simple nucleic acid, composed of a chain of only one single, repeated letter - the nucleotide uracil, or U. Using this nucleic acid, the system produced a protein that also contained a single letter, but now written in the protein language: the amino acid F, phenylalanine. By showing that a strand of U triplets was indeed the template for the amino acid phenylalanine they cracked the first letter of the code.

for the rest you can go to Google and type in Crack the Code: How the code was cracked and it will give you all the knitty gridy stuff.

Hope it helped

(espically for AP Biology!)