Mark Scheme (selected)

1. B; 2. B; 3. B; 4. B. (4) 5. 45 = 0010 1101 (1). 6. 1011 = B, 0010 = 2 → B2 (1 for each nibble) (2). 7. RAM = volatile, holds running programs/data (1); ROM = non-volatile, holds start-up instructions (1). 8. bits = 200 × 100 × 8 = 160 000 bits (1); ÷ 8 = 20 000 bytes (1); ÷ 1000 = 20 kB (1). 9. the CPU fetches an instruction from memory (1); decodes it (1); executes it; cycle repeats (1). 10. any two factors with explanation: clock speed (more cycles/sec); number of cores (more instructions at once); cache size (faster access to data) (4). 11. MAC = unique physical address of a device, fixed (2); IP = address assigned to a device on a network, can change (2).

12 (a) LAN small/single site, WAN large/geographically spread (1). (b) all devices connect to a central switch (1); advantage: one cable failing affects only one device / easy to add devices (2). (c) DNS translates the domain name into an IP address (1); so the browser can locate the web server (1+1). (d) layering makes it self-contained / easier to develop and maintain / standardised (2). 13 (a) two of: virus (attaches to files, spreads), worm (self-replicating), trojan (disguised), ransomware, spyware — each named and described (4). (b) malicious SQL typed into an input field (1); runs against the database (1); revealing/altering data (1). (c) three of: strong passwords, two-factor authentication, encryption, firewall, anti-malware, user access levels, penetration testing — each described (6). (d) people fall for social engineering / use weak passwords / human error (2).

14 (a) primary key uniquely identifies a record (1); foreign key links to a primary key in another table (1). (b) reduces data redundancy / improves consistency (2). (c) SELECT Name, Year FROM Students WHERE Year > 9 ORDER BY Name; (SELECT fields 1; FROM 1; WHERE 1; ORDER BY 1) (4). 15 (a) 0011 0101 + 0001 1010 = 0100 1111 (2). (b) the result is too large to fit in the available bits (2). (c) the wave is sampled at intervals (1); each sample stored as binary (1); higher sample rate = more samples/sec (1) = better quality but larger file (1). 16 (a) ethical issue (privacy, digital divide, automation) explained (2); environmental issue (energy use, e-waste, manufacturing) explained (2). (b) makes unauthorised access/modification of computer material illegal (2).

17 — Levels (8): open source (free, source code modifiable, community support, but variable support/security) vs proprietary (paid, reliable support, not modifiable, licence restrictions); recommendation justified for the company.

• Level 3 (6–8): Discusses both with developed pros/cons and a justified recommendation.
• Level 2 (3–5): Some pros/cons, basic recommendation.
• Level 1 (1–2): Simple statements.

Sample Answers with Examiner Commentary

Question 17 — Sample Answers

Grade 9 answer "Open source software, such as Linux, has its source code freely available, so the company could modify it to fit their exact needs and there are no licence fees, reducing costs. It often has a large community providing updates. However, professional support may be limited, and the company would need in-house technical expertise to maintain and secure it. Proprietary software, such as Windows or Adobe products, comes with reliable vendor support, regular security updates and warranties, but it has licence costs, the source code cannot be modified, and the company is dependent on the vendor.

For a company without a strong in-house IT team, I would recommend proprietary software for its core systems because the guaranteed support and security reduce business risk, even though it costs more. If the company had skilled developers and wanted to customise its tools, open source would become the stronger choice. The best approach may be a mix — proprietary for critical systems and open source where customisation and cost savings matter most." Mark: 8/8. Examiner commentary: Balanced discussion with developed advantages and disadvantages of both, real examples, and a justified, conditional recommendation. Top of Level 3.

Grade 6 answer "Open source is free and you can change the code but there might not be much support. Proprietary costs money but you get support and updates. I think the company should use proprietary because it is more reliable." Mark: 5/8. Examiner commentary: Correct core pros/cons of each and a clear recommendation, but the points are brief and there are no examples or developed reasoning about the company's situation, which would lift it into the top band.

Question 8 — Sample Answer

"File size = width × height × colour depth = 200 × 100 × 8 = 160 000 bits. 160 000 ÷ 8 = 20 000 bytes. 20 000 ÷ 1000 = 20 kB." Mark: 3/3. Examiner commentary: Correct method through bits → bytes → kilobytes with the right answer.