Ribosomal subunits are manufactured by the _____. 11:39 Biology Chapter 6 Ribosomal subunits are manufactured by the _____. A) peroxisome B) lysosome C) smooth endoplasmic reticulum D) nucleolus E) rough endoplasmic reticulum Answer: D) Ribosomes are manufactured by the nucleolus Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+