Question

Membrane bound organelles of a cell include
(A). Endoplasmic reticulum
(B). Ribosomes
(C). Lysosomes
(D). Mitochondria
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (C) and (D) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

Common non-membrane-bound cellular structures include:
- Ribosomes
- Centrosomes Centrioles
- Cytoskeletal elements (Microtubules, Microfilaments)
- Nucleolus

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Eukaryotic cells are highly compartmentalized, containing various internal structures called organelles.
These organelles are classified into membrane-bound and non-membrane-bound categories based on the presence of a surrounding lipid bilayer.
Membrane-bound organelles allow different chemical microenvironments to exist within the cell.

Step 2: Detailed Explanation:
Let us analyze each organelle listed in the question:
- (A) Endoplasmic reticulum (ER): It is a continuous system of membrane-enclosed sacs and tubules.
It plays a key role in lipid synthesis, protein folding, and calcium storage, making it a single-membrane-bound organelle.
- (B) Ribosomes: They are non-membranous macromolecular complexes composed of ribosomal RNA (rRNA) and proteins.
They are responsible for protein synthesis and are found free in the cytoplasm or attached to the rough ER.
Because they lack any surrounding membrane, they are present in both prokaryotes and eukaryotes.
- (C) Lysosomes: These are single-membrane-bound acidic vesicles containing hydrolytic enzymes.
They function as the waste disposal and recycling system of the cell.
- (D) Mitochondria: These are double-membrane-bound organelles responsible for aerobic respiration and ATP generation.
They contain their own DNA and ribosomes.
From this analysis, (A), (C), and (D) are membrane-bound organelles, while (B) is non-membrane-bound.

Step 3: Final Answer:
The membrane-bound organelles are (A), (C), and (D) only.