Final answer:
The endoplasmic reticulum or the mitochondria might be functioning incorrectly if there is a problem with lipid production in cells.
Step-by-step explanation:
If there is a problem with lipid production in cells, the part that might be functioning incorrectly could be the endoplasmic reticulum (ER) or the mitochondria. The endoplasmic reticulum is responsible for the synthesis and transport of lipids, while the mitochondria is involved in the production of acetyl-CoA, a key molecule in lipid synthesis. If either of these organelles is not functioning properly, it can lead to a decrease in lipid production within cells.