Who was responsible for "cracking the code" of DNA by establishing what amino acids are coded for by which codons, and when was this accomplished?

The correct answer is- Nirenberg and Heinrich, 1961.

Explanation:

Experiments by Marshall Nirenberg and Heinrich Matthaei in 1961, began to decipher genetic codes and state about the 64 triplet codons in the genetic code by using mRNA from DNA to translate into specific amino acids in our biological system.

Their experiment helps to decode or crack the code of DNA by establishing the first codon out of 64 triplet codes which are  UUU codes for phenylalanine. In the future, the same approach is used to find other amino acids.

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101