The exam system in England and Wales needs reform, and for many subjects that means a return to traditional exams and less coursework, according to the education secretary, Michael Gove.

In an interview in the Times, Gove says that, like Tony Blair, he is pushing the academy system. He goes on to say: "It has become easier to get an A at A-level or GCSE than it used to be, and that's a problem … If you are doing art or geography, you've got to have a work of art or a field trip. But if you're doing mathematics or English or French then the logical thing is to have a proper rigorous exam at the end of year 11 [GCSEs]."

Gove said there had been previous attempts to make science relevant, by linking it to contemporary concerns such as climate change or food scares. But he said: "What [students] need is a rooting in the basic scientific principles, Newton's laws of thermodynamics and Boyle's law."

His daughter did not understand the way history was taught, Gove said, because it was not chronological: "My daughter does toys through the ages, then she does the Vikings, then the Greeks; and she gets confused."

He added: "We are now seeing with the new exams regulator how we can make GCSEs tougher. Exam boards need to sharpen up their act. We are also saying in GCSEs that you need to award marks for spelling, punctuation and grammar. We need to have stretching exams which compare with the world's most rigorous."

Gove would welcome school heads taking a lesson from business: "We now have great headteachers who will become educational entrepreneurs. They will build a brand and create chains."

He said he would have no "ideological objection to profit-making institutions" in education – but schools did not need to be profit-making: "I think a profit motive would turn the academies movement from something that is all about philanthropy and generosity into something that was seen in a different light."

The education secretary also thinks that, in A-levels, state schools are suffering at the expense of private schools, which are opting for a more traditional-style exam, the Pre-U.

He said: "If private schools are having an elite qualification and state schools are being left with a qualification that can't match it, that is of profound concern to me, so we do need to do something to strengthen confidence in A-levels."