Question

Which of the following organelles are common to both prokaryotic and eukaryotic cells?

Plasma membrane, ribosomes, and cytoplasm

Cytoplasm, nucleolus, and ribosomes

Ribosomes, nucleoid, and golgi apparatus

Answer 1

The prokaryotic cells and the eukaryotic cells differ by a lot of things and one of their differences is the presence of organelles in eukaryotic cells which may not be present in the prokaryotic cells or vice versa. Among the choices, the answer would be the first choice: plasma membrane, ribosomes, and cytoplasm. 

Answer 2

The correct answer would be Plasma membrane, ribosomes, and cytoplasm.

Plasma membrane or cell membrane is a phospholipid bilayer that physically separates the intra-cellular content from extra-cellular environment. It is present in prokaryotic as well as eukaryotic organisms.

The cytoplasm is a gel-like compound found inside the plasma membrane. In eukaryotic cells, the cytoplasm is everything inside the plasma membrane excluding the nucleus. prokaryotic cells lack nucleus and thus the cytoplasm is everything inside the plasma membrane.

Ribosome is a molecular machine made up of rRNA (ribosomal RNA) and proteins. They are present in the cytoplasm and act as the site for protein synthesis in both prokaryotes and eukaryotes. In prokaryotic cells, usually 70S ribosomes are found whereas in eukaryotic cells 80S ribosomes are found.

In contrast, membrane bound organelles such as nucleus, mitochondria, Golgi apparatus et cetera are only present in eukaryotic cells.