The proportion of GCSE exams graded C and above has risen, official figures show.
Early indications show that some schools would see turbulence in results this year, due to changes from modular exams throughout GCSE courses to final exams, as dictated by former Education Secretary, Michael Gove.
But just over two thirds (68.8 from 98.8 gaining an A*, down from 6.8 of English entries scored a C or higher this year, down 1.9 percentage points from last summer.
This is believed to be the biggest drop in the qualification's history.
Maths saw an opposite result, with 62.423FFEB00&videoControlDisplayColor= drop in early entry across all subjects.
JCQ also said that the fall in English grades could be down to strong candidates taking advantage of a final opportunity to sit the exam last winter, and a switch by students to take an International GCSE (IGCSE) in the subject.
The statistics show that the gender gap has widened at grade C and above this year, with 73.1 of boys.
But boys are closing the gap at A*, with 5.2 of girls', a difference of 2.9 percentage points, down from three percentage points last summer.
The figures released today revealed a move away from children studying the three sciences separately, the first drop in 10 years.
All three sciences recorded double-digit percentage declines, with biology entries down by almost a fifth (18.6 and 14.6 from 451,433 to 374,961, sparked by a 34.4).
This has led to a 6 rise across the board in language entries last year.
Michael Turner, director general of the JCQ, said: "There has been a significant amount of change to the system this year and although UK level figures are relatively stable we expect more schools and colleges to see volatility in their results.
"The extent of this volatility will depend on how much change from their usual practices they experienced and how they adapted.
"Entry patterns are very different this year. We have seen a dramatic decline in the number of entries from 15-year-olds, which is largely due to a change in the school accountability measure, where a candidate's first entry counts in performance tables, and the move to end-of-year exams in England.
"As we would expect, where the change in entry patterns is greatest, such as the sciences, English and maths, we have seen some impact on results.
In an open letter to schools and colleges, the JCQ said that those institutions that had traditionally made use of the winter exam season, entered pupils early, or made greater use of resitting are likely to have seen the greatest changes in results this year.
AQA chief executive Andrew Hall said that the biggest impact on exam results this year had been from schools not letting students sit exams early, whereas before they could sit multiple times from 15.
Maths and science were among the subjects most likely to be taken by 15-year-old students under the old regime, he added, with those subjects' results affected this year accordingly.
He said: "What I think is really of note is the change in the 15-year-old results overall. What is driving that is the 'first result counts'. Only the students who are really strong in the school's judgment are being entered at 15, whereas before they were being entered to see how they get on."
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