Final answer:
The true statement is that transcription occurs in the nucleus and translation occurs in the cytoplasm. Amino acid chains form proteins, not DNA, and uracil is found in RNA in place of thymine.
Step-by-step explanation:
The true statement among the options provided is: b. The site of transcription is within the nucleus, whereas the site of translation is in the cytoplasm.
In eukaryotic cells, DNA is located within the nucleus, and the process of transcription, where DNA is used as a template to produce messenger RNA (mRNA), occurs there. After transcription, the mRNA molecule travels out of the nucleus and into the cytoplasm, where translation occurs. Translation is the process by which the mRNA sequence is used to synthesize a polypeptide chain (protein) at the ribosome.
Contrary to the other statements provided, amino acid chains do not form DNA, they form proteins. Uracil is present in RNA, not DNA, where it replaces thymine.