Question 29

Cell membrane is present in both prokaryotic and eukaryotic cells.

The cell membrane is a fundamental structure found in both prokaryotic and eukaryotic cells, serving as a barrier that regulates the entry and exit of substances.

A) Cell membrane

This option is correct because the cell membrane, also known as the plasma membrane, is essential for all cell types. It provides structure, support, and protection while controlling the movement of substances in and out of the cell, functioning in both prokaryotic and eukaryotic organisms.

B) Chromoplast

Chromoplasts are specific types of plastids found primarily in plant cells, particularly in eukaryotic organisms. They are involved in pigment synthesis and storage but are not present in prokaryotic cells, making this option incorrect.

C) Golgi apparatus

The Golgi apparatus is an organelle found exclusively in eukaryotic cells, involved in modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles. Prokaryotic cells lack this structure, rendering this option incorrect.

D) Endoplasmic reticulum

The endoplasmic reticulum (ER) is a complex organelle that exists only in eukaryotic cells, playing a critical role in the synthesis of proteins and lipids. Since prokaryotic cells do not possess an endoplasmic reticulum, this option is also incorrect.

Conclusion

The cell membrane is the only structure listed that is universally present in both prokaryotic and eukaryotic cells, providing essential functions in cellular integrity and transport. In contrast, the other options are specific to eukaryotic cells and do not exist in prokaryotic cells, which confirms that A is the definitive correct answer.