Final answer:
Protein synthesis involves the creation of mRNA from DNA in the nucleus and the translation of mRNA by ribosomes in the cytoplasm to make proteins, with tRNA providing the necessary amino acids.
Step-by-step explanation:
The correct description of protein synthesis is that DNA is a template for protein synthesis. During transcription, mRNA is formed in the nucleus using DNA as a template. This mRNA then travels out of the nucleus into the cytoplasm to the ribosomes, carrying the genetic instructions necessary for protein creation. The ribosomes then translate the genetic code contained in the mRNA to synthesize proteins in a process called translation, which sequentially strings amino acids together to form polypeptides. Ribosomes are essential components in this process, and tRNA plays a critical role by carrying amino acids to the ribosome for incorporation into the growing polypeptide chain.