Question

All organisms contain dna, and every organisms DNA is made up of 4 nucleotides. the difference between organisms is simply based on there order of these nucleotides. since all organisms have the same basic universal structure for dna, which of these must be universal?
A. All organisms have the same proteins
B. All living things must have the same amount of DNA
C. All organisms must be genetically identical to each other.
D. All matching codons in all organisms DNA code for the same amino acids.​

Answer 1

All matching codons in all organisms DNA code for the same amino acids.

Option D.

Explanation:

Codons are defined as group of three nucleotide bases that forms a triplet, and codes for a particular amino acid.

There are four nitrogen bases, so four possible nucleotides. Among them, 3 are stop codons, rest 61 are codons denoting the 20 amino acids. Codons are discrete, meaning no same codon codes for more than 1 amino acid.

And these codons are universal. It means, like AUG denotes for amino acid methionine, and that is same in bacteria, as well as in all organisms. So they are universal.