Non-membrane bound cell organelles found in both prokaryotic and eukaryotic cells are ____.

Core Logic

The nucleolus is a non-membrane-bound structure in the nucleoplasm.

It is the primary site for active ribosomal RNA (rRNA) synthesis. Cells that are highly active in protein synthesis have larger and more numerous nucleoli.

Step 1: Analyzing Other Options

• Chromatin: Contains DNA and basic proteins (histones).
• Centrosome: Organelle containing two centrioles, involved in cell division.
• Kinetochore: Disc-shaped structure on the sides of centromeres where spindle fibers attach.

Pattern Recognition

Direct factual recall: Nucleolus = rRNA synthesis factory.

Chapter Mix

Class 11 Biology: Cell The Unit of Life

Core Logic

Statement A is incorrect because the endomembrane system includes the endoplasmic reticulum, Golgi complex, lysosomes, and vacuoles, but does not include mitochondria. Statement E is incorrect because the mitochondrion is a double membrane-bound cell organelle, not a single membrane-bound structure. Statements B, C, and D are factually correct descriptions of the RER, semiautonomous organelles, and the cytoskeleton respectively.

Pattern Recognition

Mitochondria and chloroplasts act independently and are NOT part of the coordinated endomembrane system. They are also both double-membrane bound with their own circular DNA.

Chapter Mix

Class 11 Biology: Cell The Unit of Life

Core Logic

Statement C is incorrect for eukaryotes because mesosomes (extensions of plasma membrane into the cell) are found only in prokaryotes. Eukaryotes lack such structures. Statement E is incorrect in this context as the distinct glycocalyx layer described typically forms the outermost layer of the cell envelope in prokaryotes, though eukaryotes have glycoproteins/glycolipids. Statements A, B, and D correctly describe the eukaryotic cell membrane (e.g., human RBC membrane has ~52% protein and ~40% lipids; lipid bilayer with hydrophobic tails inside).

Step 1: Final Conclusion

Hence, only statements A, B, and D are correct.

Pattern Recognition

Mesosomes = prokaryotes. Eliminate any option with C for eukaryotes.

Chapter Mix

Class 11 Biology: Cell The Unit of Life