Option 1 is incorrect. Prokaryotic cells do not possess a nucleus. Unlike eukaryotic cells, prokaryotic cells lack a membrane-bound nucleus and other membrane-bound organelles.

Option 2 is correct. The cell membrane, also known as the plasma membrane, is present in both plant and animal cells. It is a selectively permeable barrier that surrounds and encloses the cytoplasm of a cell, separating it from the external environment.

Option 3 is incorrect. Mitochondria and chloroplasts are found in eukaryotic cells. Mitochondria are responsible for energy production through cellular respiration, while chloroplasts are involved in photosynthesis. These organelles are absent in prokaryotic cells.

Option 4 is incorrect. Ribosomes are present in both prokaryotic and eukaryotic cells. Ribosomes are small structures responsible for protein synthesis. They can be found free in the cytoplasm or attached to the endoplasmic reticulum in eukaryotic cells.

In conclusion, the correct statement among the options provided is option 2, which states that the cell membrane is present in both plant and animal cells.