New, tougher GCSEs are giving teenagers a better knowledge of English and maths, the Education Secretary has said.
Justine Greening said pupils are now "truly understanding" key concepts taught in the two subjects, as she defended the Government's focus on raising standards in England's schools.
She said she had been told by teachers that they saw the old exam system as simply "jumping through hoops" to get youngsters to pass.
Under a major shake-up, new GCSEs, which have less coursework and exams at the end of the course rather than throughout, are being gradually introduced, with the first grades awarded in English and maths - the first two subjects to be reformed - this summer.
At a hearing of the Commons Education Select Committee, Thelma Walker, Labour MP for Colne Valley, told the minister that many primary schools feel under pressure to "teach to the test" to ensure that children get good results in the SATs tests at age 11.
The final year of primary school is often spent on test booklets, with other subjects squeezed out, she suggested, adding that the tests "rather than being a waistcoat are a straitjacket".
Ms Greening said she would not agree with this description, arguing: "We have focused on standards in schools.
"I think we needed to do that because when you looked at the many, many young people who were coming out of our school system unable to have mastered even the basics of reading and writing, that was such a waste of their potential, and also the messages we were getting back from employers were that they were getting young people turning up for work who apparently had good qualifications but actually couldn't write properly.
"So we have through the whole curriculum, both primary and secondary, sought to raise standards, and we have pushed actually to get children up to a higher level, but they are reaching those standards and I think that's the right thing to do for them.
"If you look at the changes to GCSEs, all I can tell you is the anecdotal messages I've got back from certainly teachers in relation to GCSEs.
"They saw the previous approach as more jumping through hoops to get their children through GCSEs.
"The level of problem-solving they now have to get their students to do is much more challenging, but actually those young people are coming through with GCSEs on maths and English truly understanding the concepts they are being examined on.
"Yes, we've pushed for standards but the good news is our young people are able to reach a higher standard, our teaching profession is absolutely able to get them to that standard and I think we should all be celebrating that."