Question

structure number 7 is - a polypeptide chain (protein). transcription. a dna molecule. a nucleotide.

Explanation:

The image depicts the process of protein synthesis. In the process of translation, ribosomes (structure 5) assemble amino acids (carried by tRNA, structure 6) into a chain. This chain is a polypeptide, which will fold into a functional protein. Transcription (process of making mRNA from DNA) occurs in the nucleus (not structure 7). A DNA molecule is in the nucleus (structure 1 - pre - mRNA is being formed from DNA). A nucleotide is a building block of nucleic acids (DNA/RNA), not the structure shown as 7.

Answer:

a polypeptide chain (protein).