Some steps involved in DNA replication and protein synthesis are summarized in the table below. Step A
DNA is copied, and each new cell gets a full copy.
Step B Information is copied from DNA into mRNA which leaves the nucleus.
Step C
Proteins are assembled at the ribosomes.
Step D
Proteins fold and begin functioning.
In which step would a mutation lead directly to the formation of an altered gene?
A
Step A
B
Step B
C
Step C
D
Step D

In the nucleus, DNA is complexed with proteins to form a fine filamentous material ... so it can give complete and identical copies of all of its genes to each daughter cell. ... The process of reading an mRNA molecule and synthesizing the protein ... DNA guides the folding of a new protein after it has been assembled by RNA.

Explanation:TranscriptionProcess during which a DNA sequence of a gene is copied to make an RNA molecule

TranslationProcess during which an mRNA molecule is used to assemble amino acids into polypeptide chains

MutationA change in a genetic sequence