Question

Informosomes are composed of
A) rRNA & proteins
B) mRNA & proteins
C) mRNA & lipid
D) DNA & proteins

Answer 1

Hint: Informosomes are cellular particles found universally in all eukaryotic cells. It is the form in which the messenger RNA is transported from the nucleus to the site of protein synthesis in the cytoplasm.

Complete Answer:
Messenger RNA in eukaryotic cells is always bound with various proteins that mean it always exists in the nucleoprotein form. It never exists naked.
The ribonucleoproteins that consist of non-translatable (non-ribosomal) mRNA bound to a special protein are called messenger nucleoproteins or Informosomes.
The special protein present in Informosomes probably serves to protect the mRNA from any kind of degradation during its transport from nucleus to cytoplasm, and also to regulate the rate of translation, i.e., protein synthesis.
Informosomes were first discovered in 1964 as free mRNA containing protein particles of fish embryo cytoplasm.

On the basis of their function, the Informosomes are of different types –
1) Nuclear Informosomes: required for the biogenesis, processing and transport of mRNA.
Free cytoplasmic Informosomes: exists in a temporarily inactive state.
2) Polyribosomal Informosomes: functions as a template.

Informosomes are messenger nucleoproteins in which mRNA is present as nucleic acid, and the term nucleoprotein clearly shows the presence of proteins, thus, the correct answer is B, i.e., mRNA & proteins.

Note: The ribonucleoproteins particles of a non-ribosomal nature are called Informosomes. They play a major role in the transfer of messenger RNA from nucleus to cytoplasm (translation site) for further procedure of protein synthesis.