In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.
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Question: Question: An essential characteristic of plasmids is:
Options: <0> Be able to integrate into the genome of the host cell. <1> Direct the process of bacterial conjugation. <2> Carry genes for antibiotic resistance. <3> Replicate autonomously. <4> Being circular DNA molecules.

Answer: biology

Question: Question: What is the purpose of the phthalyl group in phthalisulfatiazole ?:
Options: <0> Improve intestinal absorption. <1> Prevent intestinal absorption. <2> Improve the passage through the blood-brain barrier. <3> Prevent passage through the blood-brain barrier. <4> Increase the affinity towards the therapeutic target of the drug.

Answer: pharmacology

Question: Question: In a three-point test crossover study, a negative interference indicates that:
Options: <0> More double crossings have occurred than expected. <1> There have been fewer double crossings than expected. <2> The match coefficient is less than 1. <3> A simple crossover decreases the likelihood of a double crossover occurring. <4> There have been fewer simple cross-links than expected.

Answer:
biology