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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 604 exam-style questions, each with its mark scheme and example answers. Print it, or answer it on paper and then open the mark schemes. Or browse the questions by topic.

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4 questions · 11 marks

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1Multiple choice1 markCharacter Sets Swap Remove

ASCII is a character set used for representing text.

Identify the number of bits used to encode each character in ASCII.

[1 mark]
  • A6
  • B7
  • C8
  • D16
Mark scheme
  • B 7 (1)
  • The only correct answer is B. The correct answer is 7 bits.
  • A is not correct because 6 bits give only 64 different characters
  • C is not correct because 8 bits are used by extended ASCII to give 256 characters
  • D is not correct because 16 bits give 65 536 different characters, which is far more than the 128 in ASCII
Example answers and how they were marked
Full marks1/1

B 7

Why: B is the only correct answer: each ASCII character is encoded using 7 bits (1).

No marks0/1

C 8

Why: Near miss scoring 0: 8 bits is extended ASCII, and the scheme's C line says extended ASCII, not ASCII, is not the answer.

No marks0/1

A 6

Why: Misconception scoring 0: 6 bits give only 64 different characters, so it cannot be ASCII.

2Short recall2 marksStored Program Computers Swap Remove

The central processing unit (CPU) contains an arithmetic logic unit (ALU).

State two types of operation carried out by the ALU.

[2 marks]
Mark scheme

Award one mark for any of the following up to a maximum of two marks:

  • An arithmetic operation, e.g. addition/subtraction/multiplication/division (1)
  • A logical operation, e.g. comparing two values (is A > B?) / using AND, OR, NOT (1)

Do not accept decoding instructions, fetching instructions or controlling the timing of the CPU, as these are carried out by the control unit.

Example answers and how they were marked
Full marks2/2

It carries out arithmetic operations such as addition and subtraction, and logical operations such as comparing two values to see if one is greater than the other.

Why: Arithmetic operation (1) and logical operation (1).

Some marks1/2

It adds numbers together and works out the result.

Why: Arithmetic operation, addition (1). No logical operation.

No marks0/2

It decodes the instructions that have been fetched from main memory.

Why: Decoding and fetching are the control unit's role; the mark scheme's do-not-accept line covers this.

3Describe2 marksUtility Software Swap Remove

A student has a large number of photographs stored on a computer.

Describe the purpose of data compression software.

[2 marks]
Mark scheme

Award up to two marks for a linked description such as:

  • Makes a file/files smaller (1) so less storage space is needed on the disk (1)
  • Reduces the size of the data (1) so it takes less time to upload/download/transfer the file (1)
  • Compresses files/folders into a single file (1) so an attachment is under the size limit for email (1)
  • Reduces the size of the files (1) so more of them fit onto a storage device/backup media (1)

Do not accept 'it compresses the files' on its own, as this repeats the question.

Do not accept responses about protecting files from malware/viruses or about deleting files.

Example answers and how they were marked
Full marks2/2

It makes the files smaller (1) so that they use less storage space on the computer and more of them fit on the disk (1).

Why: The point (1) and a linked development giving the benefit (1).

Some marks1/2

It makes files smaller.

Why: This is the point (1) but there is no development of what the smaller size leads to, so only one mark.

No marks0/2

It protects the files from viruses so that they cannot be damaged.

Why: This describes anti-malware software, which the mark scheme does not accept; no creditworthy point is made.

4Discuss6 marksUtility Software Swap Remove

A charity has 15 laptops used by staff and volunteers. Staff often download files from the internet and open email attachments. The charity's manager is considering installing anti-malware software on every laptop.

Discuss the use of anti-malware software to protect the charity's computers.

Your answer should consider:

  • how malware could affect the charity's computers
  • how anti-malware software finds and deals with malware
  • what else the charity must do for the anti-malware software to be effective
[6 marks]
Mark scheme

Indicative content

How malware could affect the charity's computers

  • A virus could damage or delete the charity's files, such as its records of donations.
  • Spyware could record keystrokes and send staff passwords or personal data to a hacker.
  • A Trojan horse could hide malicious code inside a useful-looking program that a volunteer downloads, so it is installed without the user knowing.
  • Malware could spread from one laptop to another through files shared on the charity's network, so more laptops become infected and more files are lost.

How anti-malware software finds and deals with malware

  • It scans files and compares their code with a database of known malware patterns (signatures) to identify a match.
  • It can apply rules (heuristics) to decide whether a program is behaving suspiciously.
  • A suspicious file can be run in a sandbox to see whether its behaviour is malicious.
  • When malware is found, the file is quarantined so that it cannot run, and it can be deleted.
  • Downloads and email attachments can be scanned before a member of staff opens them.

What else the charity must do for the anti-malware software to be effective

  • The database of malware definitions must be kept up to date, or new malware will not be recognised.
  • Staff and volunteers should be trained not to open unexpected attachments or download from unreliable sites.
  • Backups are still needed, because anti-malware cannot repair files that malware has already damaged.
  • Scheduled scans must be allowed to run on all 15 laptops, so that malware is found even if no one opens the file.

Levels

  • Level 0 (0 marks): No rewardable content.
  • Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
  • Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
  • Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 responses must cover both how malware could affect the computers and how anti-malware software finds or deals with it; a brief deal-with point and an unexplained update point, with no identification method and no effect on the charity's files, are Level 1.

Do not accept anti-malware software described as a firewall, or 'scans files'/'finds viruses' on its own as a method of identifying malware.

Example answers and how they were marked
Full marks6/6

A virus could spread through the files the volunteers download and delete the charity's donation records, and spyware could record staff keystrokes and send passwords to a hacker. The anti-malware software would scan each laptop, including downloaded files and email attachments, and compare their code with a database of known malware patterns. If a match is found, the file is quarantined so that it cannot run, and it can then be deleted, so one infected laptop is less likely to pass malware to the other 14. The database of definitions must be kept up to date, because new malware will not be recognised by an old database. The manager should also train staff not to open unexpected attachments, and keep backups, because anti-malware cannot repair files that have already been damaged.

Why: Level 3: the effects of a virus and spyware are applied to the charity's laptops and records, and signature comparison, quarantine and deletion are explained and linked to stopping the spread (AO1/AO2), with accurate limits on what the software can do.

Some marks2/6

The anti-malware software scans the laptops and finds viruses. When it finds one it deletes the file so the laptop is safe. The charity should keep the software updated.

Why: Level 1 (2 marks): basic, independent points are made — deleting the infected file and keeping the software updated — but there is no identification method (signatures, heuristics or a sandbox), no explanation of how malware could affect the charity, and little linkage or application.

No marks0/6

The anti-malware software is a firewall that stops hackers getting into the laptops from the internet, and it scans the files for viruses.

Why: Level 0: describing anti-malware as a firewall is a misconception and is not credited, and bare 'scans the files for viruses' is not accepted on its own as a method of identifying malware, so there is no rewardable content.

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