What are made up of DNA and provide the instructions to make proteins?

Genes are segments of DNA that contain the specific sequences of nucleotides necessary to encode the information for making proteins. They serve as templates for protein synthesis, defining the amino acid sequence that makes up each protein. The process begins with transcription, where a gene's information is transcribed into messenger RNA (mRNA), and subsequently, translation occurs in the ribosome where the mRNA is read to assemble the corresponding amino acids into a protein.

Chromosomes, while they do contain genes, are larger structures made up of DNA and proteins that organize and condense the genetic material within a cell. Enzymes are proteins themselves that facilitate biochemical reactions but do not inherently contain genetic information. Nucleotides are the building blocks of DNA and RNA, but they do not directly provide the instructions for protein synthesis; rather, they are the components that form the genes which do provide those instructions. Hence, genes are specifically the correct answer as they are responsible for coding the proteins necessary for cellular functions and growth.