Question

Agar-agar is derived from
a) A fungi
b) An algae
c) Both A and B
d) A bryophyte

Answer 1

Hint: They are chlorophyll-bearing, autotrophic thallophytes, mainly seen in aquatic environments.

Complete answer: The gelling agent present in agar is an unbranched polysaccharide obtained from the cell walls of some species of red algae. These algae are known as agarophytes and they belong to the phylum Rhodophyta (red algae). Agar-agar is one of the commercial products from algae that are used to grow microbes. Agar is a gelatinous mixture of non-nitrogenous extracts from Rhodophyceae algae. Agarose and agaropectin are the two components of agar. The important agar sources are Gelidium, Gracilaria, Gigartina, Chondrus, Hypnea, etc. Its melting point is between 90 and 100 ° F. At lower temperatures, it changes into solid. Agar is insoluble in cold water and soluble in hot water. It is toxic to humans, and sometimes people have allergic reactions while using it. Agar has no taste, no odor, and no colour, so it is convenient to use.
Uses of algae:
Agar has several uses in the food and pharmaceutical industries.
In the food industry, it can be used as a thickening agent in soup and sauces. It is widely used in fruit jellies, ice creams, and jams.
In the pharmaceutical industry, agar is used in the preparation of pills and dental impressions.
Agar is used as a base for different culture media. Often, Neomycin agar is used for culturing organisms anaerobically.
Agar is also used for the preparation of bases for cosmetic, leather, and paper industries.
Pure agar is used as a gel in electrophoresis and chromatographic studies.

So, the correct answer is an ‘algae’.

Note: Electrophoresis is a method used in laboratories to separate DNA, RNA, or protein molecules based on their size and electrical charge. Chromatography is a method used in laboratories for the separation of a mixture.