do you mean codons? codons are in the mRNA and it completes the process of of protein sythesis. mRNA leaves the nucleus and connect with a ribosome. that's where the codons on the mRNA are translated from the nucleic acids to amino acids langage.
The structure you are referring to is called the centromere. It is a region of DNA found on each chromosome that holds the two copies, or sister chromatids, together before cell division takes place. The centromere is important for ensuring accurate distribution of genetic material to each new cell. To find this answer, one can break down the question into specific details. In this case, you mentioned that the structure begins with a "C" and has "d" as the second to last letter. By focusing on these clues, it becomes apparent that the word "centromere" fits the description.
