Question

The prokaryotic cell is the most simple of these two. You may recall that, unlike eukaryotes, prokaryotic cells do not have membrane-bound organelles. Their genome, composed of double-stranded DNA, is just floating in the cytoplasm in the shape of a circle; we call this the nucleoid. Eukaryotic cells, on the other hand, have membrane-bound organelles. This means that DNA can be stored elsewhere, perhaps to protect the genetic information or to make it easier to find (like storing your socks in one dresser). Most of the eukaryotic genome is stored in the nucleus, and it is found in the vast majority of eukaryotic cells*. The rest of the DNA can be found in the mitochondria, another membrane-bound organelle which is responsible for cellular respiration (that is, the process of making ATP for energy). If you're having trouble remembering that small fraction of mitochondrial DNA that exists independently of the nucleus, familiarize yourself with the endosymbiotic theory. To summarize, scientists think the mitochondria was a cell of its own, complete with its own genome, which one day entered symbiosis with a larger host cell. A symbiotic relationship means that each player (the mitochondria and the host cell) benefit from it (unlike a parasitic relationship). Knowing this, we can recognize that there ought to be two locations of DNA in the modern-day eukaryotic cell, as opposed to one in the prokaryotic cell.

Answer 1

Prokaryotic cells are simple and lack membrane-bound organelles with DNA within a nucleoid region. Eukaryotic cells contain a membrane-enclosed nucleus and other organelles. The mitochondria in eukaryotic cells possess their own DNA, supporting the endosymbiotic theory which posits that mitochondria were once prokaryotic cells.

Step-by-step explanation:

Differences Between Prokaryotic and Eukaryotic Cells

Prokaryotic cells are simpler in structure compared to eukaryotic cells. They lack a membrane-bound nucleus and other organelles, instead containing their DNA within a nucleoid region. Their DNA is typically a single, circular molecule that resides freely in the cell's cytoplasm. On the other hand, eukaryotic cells possess a nucleus enclosed by a membrane, where most of their genetic material is organized into chromosomes. Eukaryotic cells also contain other organelles such as the mitochondria, endoplasmic reticulum, and Golgi apparatus that compartmentalize cellular functions.

The mitochondria are particularly interesting as they contain their DNA and are believed to have been independent prokaryotic organisms at one point, according to the endosymbiotic theory. This theory suggests that mitochondria entered into a symbiotic relationship with a larger host cell, providing ATP and benefiting from protection within the host. This mutualistic arrangement explains why mitochondria have their distinct DNA separate from the nuclear DNA in eukaryotic cells.

While prokaryotes are exclusively unicellular organisms like bacteria and archaea, eukaryotes can be either unicellular or multicellular, including plants, animals, fungi, and protists. The complexity of eukaryotic cells allows for advanced functions and multicellularity in organisms.