Question

The litmus paper or the litmus solution is obtained from the plant.
A. Moss
B. Lichen
C. Rose
D. Hibiscus

Answer 1

Litmus is a water-soluble mixture of different dyes extracted from lichens. It is often absorbed onto filter paper. It is used as a pH indicator and also to test ingredients for acidity. It is obtained from a composite organism.

Complete answer: Litmus can be found in different species of lichens. Dyes are extracted from the genus Roccella. Roccella montagnei and Dendrograma leucophaea are the two main sources of litmus. Lichen is a combined organism composed of algae or cyanobacteria and filaments of many fungi species. Raw materials used for the production of litmus paper are wood cellulose, lichens. Litmus paper, as its name suggests, is composed of paper. The paper that is used to make litmus must be free from impurities because it could change the pH of the system. Like other papers, litmus paper is made from wood cellulose. The wood is treated with solvents before the paper is produced in order to remove the resin and lignin. Litmus paper can change colour when exposed to an acid or base. This ability is attained because of lichens. Lichens are a combination of two distinct organisms, a fungus and an alga, living together. Lichens are classified as fungi because fungi are responsible for sexual reproduction.
Lichen used to produce litmus includes Roccella tinctoria.
So, the correct answer is option B.

Note: The litmus paper is effective at demonstrating whether a substance is acidic or basic, but it cannot give an exact numerical pH value. Universal indicators of pH meters are used for knowing the exact pH. The Netherlands is one of the largest producers of litmus paper. Lichens are an indicator of pollution as they are sensitive to various pollutants.