Question

Which of the following are not membrane bound?
A) Mesosomes
B) Vacuoles
C) Ribosomes
D) Lysosomes

Answer 1

Organelle simply means “tiny organs”. As the body is made up of different organs, the cell also has “small organs “that Perform special functions. In general, they are membrane bounded compartments or cell structures. In strict description, the organelle is a membrane bounded compartment or a cell structure that performs a special purpose. In a less stringent definition, The organelle refers to any cellular structure, whether or not a membrane bounded structure carries a particular purpose.

Complete answer:
The eukaryotic cell comprises several organelles, such as the nucleus, the endoplasmic reticulum, the Golgi apparatus, the mitochondria and the chloroplast (plastid) . However, not all of these organelles are present in a single cell or in an organism.
Prokaryotes, which were assumed to have no organelles, have recently been identified as having their own kinds of “organelles”. However, these are referenced to them as proteinaceous micro -compartments rather than real organelles. Membrane-bound organelles are cellular structures bound by biological membranes. The membrane can be a single layer or a double layer of lipids, usually with interspersed proteins.
Option A:Mesosomes-mesosomes is membrane bounded organelles. Its plasma membrane is infolded into mesosomes which carry respiratory enzymes.
Option B:Vacuoles-vacuoles are bounded with membrane, the tonoplast is the vacuoles which separates vacuoler contents from the cell cytoplasm.
Option C:Ribosomes-ribosomes are the protein factory of the cell. These are non -membranous organelle which attach on the endoplasmic reticulum and make it a rough endoplasmic reticulum.
Option D:Lysosomes-each lysosomes is an acidic environment in cytoplasm as it contains hydrolytic enzymes.

Thus, the correct answer is option:C:ribosomes

Note:
A ribosome is a small, sphere shaped particle made up of protein and ribonucleic acid (RNA). Acts as a site of protein synthesis.