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Unit 1 Fundamentals of Computer Science

10 dot points across 10 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do we design, express and judge the efficiency of an algorithm, and which standard searching and sorting algorithms must I know?

Design algorithms in pseudocode, apply the standard searching and sorting algorithms, and compare algorithm efficiency.
A focused answer to WJEC A-Level Computer Science Unit 1 algorithms, covering algorithm design and pseudocode, linear and binary search, bubble, insertion and merge sort, and comparing efficiency.
13 min answer →

How do networks connect computers, and what roles do topologies, protocols and the internet play in moving data?

Describe networks and topologies, transmission media and methods, protocols and the TCP/IP stack, and how the internet works.
A focused answer to WJEC A-Level Computer Science Unit 1 communication, covering LANs and WANs, network topologies, transmission methods, protocols and the TCP/IP stack, packet switching, and how the internet works.
13 min answer →

How does a computer represent numbers, text, sound and images using only binary digits?

Represent numbers in binary, hexadecimal and two's complement, perform binary arithmetic, and represent characters, sound and images as binary data.
A focused answer to WJEC A-Level Computer Science Unit 1 data representation, covering binary and hexadecimal, two's complement, binary arithmetic and shifts, and how characters, sound and images are stored as binary.
13 min answer →

How do arrays, records, stacks, queues, trees and hash tables organise data, and when is each one the right choice?

Describe and use arrays, records, lists, stacks, queues, trees and hash tables, and explain their operations and uses.
A focused answer to WJEC A-Level Computer Science Unit 1 data structures, covering arrays and records, the abstract data types stack and queue, lists, binary trees and hash tables, and when each is the right choice.
13 min answer →

How is a computer built from a processor, memory and storage, and how does the fetch-execute cycle run a program?

Describe the von Neumann architecture, the components of the CPU, the fetch-execute cycle, memory and the storage hierarchy.
A focused answer to WJEC A-Level Computer Science Unit 1 hardware, covering the von Neumann architecture, the CPU components and registers, the fetch-execute cycle, primary and secondary storage, and factors affecting performance.
13 min answer →

How do Boolean logic, logic gates and truth tables describe and simplify the operations inside a processor?

Use Boolean algebra, logic gates and truth tables to represent and simplify logical operations.
A focused answer to WJEC A-Level Computer Science Unit 1 logical operations, covering the logic gates and their truth tables, Boolean expressions and identities, and simplifying a logic circuit.
12 min answer →

How is data organised in files and databases, and why does normalising a database remove redundancy and anomalies?

Describe files, fields and records, relational databases, normalisation, basic SQL, and validation and verification.
A focused answer to WJEC A-Level Computer Science Unit 1 organisation of data, covering files, fields and records, relational databases and keys, normalisation to remove redundancy, basic SQL, and validation and verification.
13 min answer →

What are the building blocks of a program, and how do sequence, selection, iteration, procedures and recursion combine to express any algorithm?

Explain the principles of programming: data types, the three control structures, procedures and functions, parameter passing and recursion.
A focused answer to WJEC A-Level Computer Science Unit 1 principles of programming, covering data types and variables, sequence, selection and iteration, procedures, functions and parameter passing, and recursion.
13 min answer →

How is data kept secure and accurate, and what laws and ethical duties govern the use of computers and data?

Describe data security threats and protection, encryption, data integrity, and the legislation and ethics governing computer use.
A focused answer to WJEC A-Level Computer Science Unit 1 security and the law, covering threats such as malware and hacking, protection measures, encryption, data integrity, and the relevant legislation and ethics.
12 min answer →

What are the layers of software, and how does the operating system manage the hardware on behalf of programs?

Describe systems, application and utility software, the functions of the operating system, translators, and modes of operation.
A focused answer to WJEC A-Level Computer Science Unit 1 software and systems, covering system, application and utility software, operating system functions, compilers, interpreters and assemblers, and modes of operation.
12 min answer →