Question

structure number 3 is - dna. mrna. trna. ribsome

Explanation:

The image depicts the process of gene expression. Structure 3 is mRNA (messenger RNA). mRNA is synthesized in the nucleus through transcription (using DNA as a template) and then moves to the cytoplasm for translation. DNA (structure 1) is in the nucleus. tRNA (transfer RNA, structure 6) is involved in bringing amino acids to the ribosome during translation. Ribosomes (structure 5) are the sites of protein synthesis.

Answer:

mRNA.