Questions & Answers

Spherosomes are formed from
(A) Nucleus
(B) Endoplasmic reticulum
(C) Ribosome
(D) Mitochondria

Answer Verified Verified
Hint: Spherosomes were discovered by Perner and are also called plant lysosomes. They are small cell organelles bounded by a single membrane that take part in the storage and synthesis of lipids. They are only found in plant cells.

Complete answer:
Endoplasmic reticulum divides intracellular space into two compartments, i.e, luminal (inside ER) and extra luminal (cytoplasm). These can extend from the nuclear envelope to the plasma membrane. The endoplasmic reticulum is composed of the following three kinds of structures (i) cisternae which occur in those cells which have synthetic roles, (ii) tubules that are involved in lipid and sterol synthesis, and (iii) vesicles that are membrane-bound vacuolar structures.
The ER is of two types:
The smooth endoplasmic reticulum consists mainly of tubules and vesicles and the rough endoplasmic reticulum consists of cisternae. It has ribosomes attached to its cytoplasmic surface. Rough endoplasmic reticulum provides a surface for protein synthesis. The proteins in the ER lumen are processed and are packed in membrane-bound vesicles for storage or export, or for further processing in the Golgi apparatus. The smooth endoplasmic reticulum is involved in fat and steroidal hormone synthesis.
Spherosomes are surrounded by a phospholipid monolayer that arises from ER and takes part in the storage and synthesis of lipids.
The nucleus was discovered by Robert Brown. It is double membrane-bound dense protoplasmic body that controls cellular metabolism, encloses all the genetic information, and is able to transmit the same to the next generation
Ribosomes were discovered by Robinson and Brown (1953) in plant cells and by Palade (1955) in animal cells. Ribosomes are naked ribonucleoprotein protoplasmic particles (RNP). The cytoplasmic ribosomes of prokaryotes (blue-green algae, bacteria, and PPLO) are the 70S. They have two subunits of ribosomes that are the 50S and 30S. Ribosomes of mammalian mitochondria have a sedimentation coefficient of 55S. The cytoplasmic ribosomes of eukaryotic are 80S type. The two subunits of 80S ribosomes are 60S and 40S. The free ribosomes synthesize non-secretory proteins, while ER bound ribosomes synthesize secretory proteins. During protein synthesis, many ribosomes form a chain on a common messenger RNA and form the polyribosomes or polysomes.
The mitochondria were first observed by Kolliker in 1850. A mitochondrion has two membranes: the outer membrane which is smooth and has porin proteins that form channels and the inner mitochondrial membrane which is semi-permeable and regulates the passage of materials into and out of the mitochondria. It usually produces numerous infolds called cristae which divide the inner mitochondrial space into many compartments. The cristae and the inner face of the inner membrane are studded with F0-F1 particles or oxysomes.

So, the correct answer is option B) Endoplasmic reticulum.

Mitochondria are semi-autonomous organelles. The oxysomes, also called F0-F1 complex, represent adenosine triphosphatase, or ATPase, or ATP synthetase enzyme and is thus concerned with ATP formation.