Read the following passage carefully and answer the given questions.
During anaerobic sludge digestion, bacteria produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide. These gases form biogas and can be used as source of energy as it is inflammable. The bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus Trichoderma polysporum. You must have noticed that bottled fruit juices bought from the market are clearer as compared to those made at home. This is because the bottled juices are clarified by the use of pectinases and proteases. Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol. The BOD test measures the rate of uptake of oxygen by micro-organisms in a sample of water and thus, indirectly, BOD is a measure of the organic matter present in the water.
Cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by -
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Trichoderma polysporum
Option (1) Aspergillus niger — Incorrect. This fungus is used to produce citric acid.
Option (2) Monascus purpureus — Incorrect. This yeast produces statins, which lower blood cholesterol.
Option (3) Trichoderma polysporum — Correct. This fungus produces cyclosporin A. It suppresses the immune system, so the body does not reject a transplanted organ.
Option (4) Bacillus thuringiensis — Incorrect. This bacterium makes the Bt toxin, a protein that kills certain insects. It is used to control butterfly caterpillars, and its cry genes are put into Bt cotton.
Note 1: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
Note 2: A similar question was also asked in CUET (UG) 2025 on 27-05-2025 (Slot 2), on 20-05-2025 (Slot 1) and on 14-05-2025 (Slot 1).