Question

The RNA is not found in
A. Chromosome
B. Plasmalemma
C. Nucleolus
D. Ribosome

Answer 1

Hint: Ribonucleic acid is a type of nucleic acid that is found in the living system. It functions as an adaptor, structural and in some cases as a catalytic molecule. They were the first genetic material of the cell that are present in many organelles.

Complete answer:
Ribonucleic acid or RNA is a polymeric molecule that is needed in biological roles in coding, regulation and expression of genes. Some RNA molecules play an active role in the cells by catalyzing biological reactions, controlling the expression of genes, and in communicating responses to cellular signals. Let us infer about the options given above:
1. Chromosomes- During different stages of cell division, cells show structured chromosomes in place of the nucleus. Chromatin contains DNA and some basic proteins called histones, some non-histones proteins and also RNA. The telomerase is the important part of the chromosome. These structures contain RNA and it protects the chromosome from being cut.
2. Plasmalemma - We also say it as plasma membrane of a cell is the outer membrane that helps in keeping the contents separate from the surrounding environment. Biochemical investigation clearly reveals that the cell membrane possesses proteins and carbohydrates. The major role of it is transportation of the molecules across it. Proteins are responsible for the maintenance of cell structure, act as receptors or take part in chemical reactions as enzymes. RNA is absent in them.
3. Nucleolus- The content in them is continuous with respect to the nucleoplasm as it is not a membrane bound structure. It is the site for active ribosomal RNA synthesis. Larger and more numerous nucleoli are present in cells actively carrying out protein synthesis.
4. Ribosome- It is a granular structure that is composed of ribonucleic acid (RNA) and proteins. These structures are not surrounded by any membrane.

So, the correct answer is option B, Plasmalemma.

Note-
RNA can direct code for the synthesis of proteins, hence can easily express the characters. However, DNA is dependent on RNA for synthesis of proteins. The protein synthesising machinery has evolved around RNA.