Choose the correct statements regarding cell organelles and their inclusions.

A. The endomembrane system includes Golgi complex, endoplasmic reticulum and mitochondria.
B. Rough endoplasmic reticulum bears ribosomes on its surface.
C. Both mitochondria and plastids have circular DNA.
D. A network of microtubules, microfilaments and intermediate filaments present in the cytoplasm is called cytoskeleton.
E. Mitochondrion is a single membrane-bound structure.

Choose the correct answer from the options given below :

To determine which statements are correct, evaluate each one against established cell biology facts.

Statement A: “The endomembrane system includes Golgi complex, endoplasmic reticulum and mitochondria.”
The endomembrane system consists of the nuclear envelope, endoplasmic reticulum (smooth and rough), Golgi apparatus, vesicles, lysosomes, and the plasma membrane. Mitochondria are not derived from the endomembrane system; they have their own double‑membrane architecture and are considered semi‑autonomous organelles.
Therefore, statement A is incorrect.

Statement B: “Rough endoplasmic reticulum bears ribosomes on its surface.”
Rough ER is characterized by ribosomes attached to its cytoplasmic surface, which enable co‑translational insertion of nascent polypeptides into the ER lumen or membrane. This description matches textbook definitions.
Thus, statement B is correct.

Statement C: “Both mitochondria and plastids have circular DNA.”
Mitochondria contain their own circular double‑stranded DNA (mtDNA). Plastids, such as chloroplasts, also possess a circular genome (cpDNA). Both organelles replicate their DNA independently of the nuclear genome.
Hence, statement C is correct.

Statement D: “A network of microtubules, microfilaments and intermediate filaments present in the cytoplasm is called cytoskeleton.”
The cytoskeleton is the structural framework of the cell, composed of microtubules, actin microfilaments, and intermediate filaments. It provides shape, mechanical support, and facilitates intracellular transport.
Consequently, statement D is correct.

Statement E: “Mitochondrion is a single membrane‑bound structure.”
Mitochondria are bounded by **two** membranes: an outer membrane and a highly folded inner membrane (cristae). The double‑membrane arrangement is essential for oxidative phosphorylation.
Therefore, statement E is incorrect.

Summarizing the evaluation, the only statements that are true are B, C and D. The correct answer is B, C and D only.