Read the following passage carefully and answer the given questions.
Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis forms protein crystals during a particular phase of their growth. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (α-1-antitrypsin) used to treat emphysema. In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 grams per litre). The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow-milk. A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infestation which was based on the process of RNA interference (RNAi). This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing). Biopiracy is the term used to refer to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment. ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.
Some strains of Bacillus thuringiensis produce proteins that do not kill certain arthropods, such as:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Crustaceans
The passage says Bt proteins kill certain insects: lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). Each Bt toxin is specific to an insect group, so arthropods outside these groups are not killed.
Option (1) Lepidopterans — Killed by Bt proteins.
Option (2) Coleopterans — Killed by Bt proteins.
Option (3) Crustaceans — Not killed by Bt proteins. Crustaceans such as crabs and prawns are arthropods but not insects, and they are not among the groups the passage names.
Option (4) Dipterans — Killed by Bt proteins.
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: The same question was also asked in CUET (UG) 2025 on 22-05-2025 (Slot 1), and a similar question in CUET (UG) 2025 on 14-05-2025 (Slot 1).