Biology (song)

"Biology" is a song performed by English-Irish all-female pop group Girls Aloud, taken from their third studio album Chemistry (2005). The progressive pop song was written by Miranda Cooper, Brian Higgins and Higgins' production team Xenomania, and produced by Higgins and Xenomania. Composed of distinct sections, it avoids the verse-chorus form present in most contemporary pop music. "Biology" was released as a single in November 2005, ahead of the album's release. Following the disappointment of "Long Hot Summer", "Biology" returned Girls Aloud to the top five of the UK Singles Chart and became their tenth top ten hit.

The music video, consisting only of group shots, witnesses Girls Aloud seamlessly moving through various sequences while performing disjointed choreography. "Biology" was promoted through a number of live appearances and has since been performed on all of Girls Aloud's subsequent concert tours. The song, which includes a variety of styles, received widespread acclaim from contemporary music critics. Considered one of Girls Aloud's signature songs, The Guardian referred to "Biology" as "the best pop single of the last decade".