Thousands of sixth-formers have joined Facebook campaigns protesting about an A-level biology paper that asked them to comment on the ethical issues involved in culling hedgehogs.

The hedgehog question is just one of a series of complaints about the OCR paper that has led more than 4,000 irate candidates to voice their outrage on the social networking website.

Many fear university places could be jeopardised by an exam on Monday which they claim was disproportionately focused on ecology - just one of the four modules on the syllabus.

They believe much of their revision and study has been wasted and have bombarded the OCR board and regulator, Ofqual, with emails amid calls to “break their servers”.

“We did not spend two years studying biology, putting in many hours to achieve the grades we all want, for it to come down to questions asking us to discuss the ethical issues around culling hedgehogs,” one candidate said.

Another pupil said: “A lot of the questions could be answered with common sense so I feel my hours of revision were undercut by this paper.”

OCR has told the candidates their “feedback” will be taken into account when the mark scheme for the paper on “Control, genomes and environment” is finalised and grade boundaries are set.