Question

All are membrane bound cell organelles except
A) Mitochondria
B) Lysosomes
C) Spherosomes
D) Ribosomes

Answer 1

Hint: 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-bound compartments or cell structures. In strict description, the organelle is a membrane-bound 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-bound 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 (plastic). 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 kind of "organelles." However, there are references 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.
Examples of membrane-bound organelles include nucleus, endoplasmic reticulum , Golgi apparatus, mitochondria, plastids, lysosomes and vacuoles.
Non-membrane-bound organelles are cytoplasmic structures that are not bound by a membrane but perform specialised functions.
Examples of non-membrane-bound organelles are ribosomes, spliceosomes, vaults, proteasomes, holoenzyme DNA polymerase III, holoenzyme RNA polymerase II, photosystem I, ATP synthase, nucleosomes, centrioles, microtubules, cytoskeletons, flagellum, nucleolus, granule stress, etc.

Thus the correct answer is option (D)Ribosomes.

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