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.

Q: Question: Kinesin and dynein are:
Options: <0> Adhesion proteins. <1> Microtubular motors. <2> Degradative enzymes <3> Components of the vesicular cover. <4> Transcriptional factors.

A: biology
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Q: Question: About free radicals:
Options: <0> They are compounds that contain two or three unpaired electrons in an outer orbital. <1> Reactive oxygen species (ROS) in the cell are only generated enzymatically. <2> Hydrogen peroxide is the most damaging radical in the cell. <3> The hydroxyl radical originates non-enzymatically (Heber-Weiss reaction) and damages proteins and DNA. <4> Oxygen is a triradical.

A: chemistry
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Q: Question: Ribonuclease H hydrolyzes specifically:
Options: <0> The DNA with DNA matching complementary sequence. <1> RNA with DNA matching of complementary sequence. <2> The RNA primer in the replication. <3> RNA without pairing with DNA of complementary sequence <4> Certain introns in the maturation process.

A:
chemistry
****