Final answer:
yeasts are eukaryotic, not prokaryotic, and their cell cycle lasts 2-4 hours, not 90 minutes.
Step-by-step explanation:
The statement that a prokaryotic yeast cell completes its cell cycle in 90 minutes . Yeasts are actually eukaryotic organisms; they contain a nucleus and organelles within their cells. A characteristic feature of eukaryotic cells is that they undergo mitosis and meiosis for cell division, processes that are more complex than the binary fission seen in prokaryotes. Additionally, while some single-celled eukaryotes can divide rapidly, the time it takes for cell division varies. For instance, the cell cycle of a typical eukaryotic cell, like yeast, can range between 2-4 hours, in comparison to the rapid 30-60 minute life cycle of a bacterium, which is a prokaryote.
Cell division in yeast can occur asexually through mitosis, where the M phase lasts approximately one-half hour. Sexual reproduction in yeast also occurs through conjugation followed by meiosis, particularly under adverse conditions. This information contradicts the notion that yeasts have cell cycles of 90 minutes and identifies them as eukaryotic, not prokaryotic.