Final answer:
RNA is synthesized in the nucleus where the process of transcription occurs. mRNA copies the DNA instructions and then carries them to the cytoplasm for protein synthesis by ribosomes. Therefore, the correct option is 3.
Step-by-step explanation:
RNA is made by copying the DNA code in the nucleus of a cell. The process of copying the genetic instructions from DNA to RNA is called transcription, and it takes place in the nucleus because that is where the DNA is located in eukaryotic cells.
After transcription, messenger RNA (mRNA), which is a type of RNA, carries the genetic instructions from the nucleus through the nuclear pores into the cytoplasm, where proteins are synthesized by ribosomes. Therefore, the correct answer to the question 'Where is RNA made by copying the DNA code?' is option 3) nucleus.
There are three types of RNA involved in protein synthesis: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). Each has a distinct role, but mRNA is the type specifically involved in carrying the genetic code from DNA in the nucleus to the ribosome in the cytoplasm, where the code is used to make proteins.