Repressors and activators, which are crucial for the regulation of gene expression, are produced within the cell. These proteins are synthesized in the cytoplasm, typically through the process of translation on ribosomes after mRNA is transcribed from DNA. Once produced, they can move into the nucleus where they exert their regulatory functions, binding to specific DNA sequences to either suppress or encourage the transcription of genes.
The mitochondria are primarily involved in energy production and do not synthesize these regulatory proteins. The nucleus serves as the site of DNA and RNA processing but is not where repressors and activators are made; rather, these proteins are produced in the cytoplasm before they enter the nucleus to perform their roles. Meanwhile, the extracellular matrix is a network that provides structural support to tissues and does not directly synthesize cellular proteins like repressors and activators. Thus, the correct location for the production of these regulatory proteins is indeed within the cell itself.