Question

Which of the following are not membrane-bound?

• A. Vacuoles
• B. Lysosomes
• C. Ribosomes
• D. Mesosomes

Answer 1

The correct option is C

Ribosomes

The correct option is C.

The explanation of the correct option:

1. Ribosomes are the non-membranous cell organelles observed in both prokaryotic and eukaryotic cells as well.
2. Ribosomes are made up of rRNA and proteins.
3. They help in manufacturing protiens.

The explanation of the incorrect options:

Option A:

1. Vacuoles are empty, irregularly circular organelles.
2. It is a membranous cell organelle, and the membrane is referred to as tonoplast.
3. They help in storage as well as discharge of waste material.

Option B:

1. The sac-shaped structures in a cell are referred to as lysosomes.
2. They help in the digestion of foreign substances as well as worn-out cell organelles.
3. It is also a membrane-bound cell organelle.

Option D:

1. Mesosome is a membranous organelle formed due to the foldings of the plasma membrane in the vesicles, tubules, or lamellar whorls.
2. They help in membrane synthesis.

Final answer: Ribosomes are not membrane-bound.