The exam season is set to begin for around 125,000 candidates in schools and colleges across Scotland.
The National 5 and Higher philosophy exams will take place on Tuesday morning.
For many candidates, the first exams will be the the National 5 Higher and Advanced Higher maths exams which go ahead on Friday.
The last exam is in early June and candidates will get their results on 8 August.
In some cases these concerns were founded, others turned out to be unjustified.
The Scottish Qualification Authority (SQA) has insisted it has tight quality control processes in place.
Dr Janet Brown, SQA chief executive and Scotland's chief examining officer, said: "I'd like to wish everyone sitting examinations and taking qualifications at schools and colleges the best of luck between now and the end of the term.
"After months of hard work and hours of study, many thousands of young people throughout Scotland are preparing to complete their qualifications and take the next step in their education or into work.
"At all levels, our qualifications provide candidates with the opportunity to demonstrate the knowledge and understanding they've acquired and prepare them for further study, employment or training.
"Our qualifications are robust, relevant, and designed to equip young people with a wide range of skills."