The work involved is science practicals done by the students at school and teachers are supposed to verify it as the candidate's own before submitting it for marking.
The science investigations, known as coursework, carries up to 35pc of the marks in the exam.
The problem occurred both among higher level and ordinary level candidates and among candidates at more than one exam centre during last year's Junior Cert.
The issue has been highlighted in a report by the chief examiner of the State Examinations Commission (SEC).
Some Ordinary Level candidates had their marks for the work involved withheld pending a satisfactory explanation from the schools, according to the report.
However, it is not known what the final outcome was for the students, who sat their exams in June 2010, as the SEC has said it does not comment on individual cases.
In cases where the SEC is satisfied that cheating has occurred, it may withhold results indefinitely or, in the worst-case scenario, ban a student from sitting future exams.
The use of coursework in assessing students is regarded as key to ensuring that students can apply their knowledge and develop necessary laboratory and science investigative skills.
The examiner's report notes that the marks awarded for science coursework were generally high, but points out that some candidates wrote "identical or very similar entries for analysis, conclusion and comment".
The report states: "The presentation of similar coursework by a number of candidates is a cause of some concern.
"Teachers and students are reminded that coursework presented and the reports thereof should be the individual work of the candidate only."
The chief examiner also criticised the way some Leaving Certificate business students memorised answers for last year's exam.
The report adds: "An over-emphasis on preparation for the examination through rote learning of answers resulted in low marks being awarded to candidates in certain questions."
Among the recommendations given to students in the report is not to rely on answers that may have been appropriate to questions in a previous year's paper.
"Questions may appear similar to previous years but the focus on the questions and the specific context of the question may vary, thereby requiring different responses," the report advises.
If you're willing to put in the work, Junior Science is one of the easier exams to prepare for as the information you need to remember is very factual i.e. no waffling. Make sure you learn your definitions as these make up a large part of the exam.
What's on the Junior certificate Science course
- Skeletal and Muscular system,
- The Senses
- Human reproduction
- Animals, Plants and Micro-Organisms
- Classification of substances
- Air, Oxygen, Carbon Dioxide
- Atomic structure
- Reactions and Compounds
- Force and Energy
- Heat, Light and Sound
- Electricity and Electronics
What's the Junior certificate Science exam like?
35% of the marks go for a report you write on an investigation carried out before the exam as well as the practical notebook you used to record experiments done in class. Your teacher will choose one investigation form a choice of three titles on each of Physics, Chemistry and Biology.
The two hour written exam has three sections. Biology is covered in Questions 1, 2 and 3, Chemistry is covered in Questions 4, 5 and and Physics is covered in Questions 7, 8 and 9.
Any tips for doing well in Junior certificate Science ?
Make sure you go over your definitions as many questions will ask you to define a key term. In Physics make sure you learn off your formulas. The exam tends to cover most of the topics so it's not a good idea to take short cuts by leaving out topics. Don't forget to go over your experiments as these always make up a big part of the exam. Practicing past exam papers is especially important in Science. Study one topic at a time and then go through that topic on Studyclix comparing your answer with the marking scheme.
Download the Junior Cert Science Syllabus
Download the Junior cert Science Chief examiner's report (2010)
Download the Junior cert Science Guidelines for Teachers