what type of cell has no nucleus or membrane bound organelles

The type of cell you're asking about is a prokaryotic cell. These are super simple compared to the cells in our own bodies, which are eukaryotic and have all those fancy membrane-bound parts. Bacteria are the most common examples of these, and they basically just have their DNA floating around in a region called the nucleoid instead of tucked away in a nice, neat nucleus.

When I’m looking at samples or thinking about how these things work, it’s honestly wild how efficient they are without all that extra machinery. Because they don't have organelles like mitochondria or the endoplasmic reticulum, everything just happens in the cytoplasm. It’s like living in a studio apartment where the kitchen, bedroom, and office are all in one room—it might look messy, but it gets the job done perfectly for them.