Final answer:
The answer to the crossword clue 'mRNA carries the _____ for DNA' is 'message'. mRNA serves as the intermediary that carries genetic instructions from DNA to the ribosome for protein synthesis during the processes of transcription and translation.
Step-by-step explanation:
The clue given in the Protein Synthesis Crossword puzzle is "mRNA carries the _____ for DNA". The answer to this clue is "message". This can also be understood as mRNA carrying the instructions for the synthesis of proteins from DNA. The process begins with transcription in the nucleus wherein a specific segment of DNA is transcribed to form mRNA. The mRNA then exits the nucleus and travels to the ribosomes in the cytoplasm where translation occurs. During translation, the message contained within the mRNA, which specifies the sequence of amino acids, is read and used to create a polypeptide chain that folds into a functional protein.
In summary, mRNA serves as the intermediary between the DNA and the production of protein products during translation. It is the essential molecule that carries the genetic code from DNA to the ribosome where proteins are synthesized according to the information provided by the mRNA sequence.