1
OCR A LEVEL COMPUTER SCIENCE EXAM
| QUESTIONS AND ANSWERS | VERIFIED
AND WELL DETAILED ANSWERS (100%
CORRECT) | LATEST EXAM UPDATE
1 Dimensional Arrays - (answers)A standard list array - one index is needed to
search for something in an array.
2 Dimensional Arrays - (answers)An array with 2 indexes needed to search - for
example a table could be this.
Interception of PseudoCode - (answers)The ability to pick out and explain parts of
code.
Big O' - (answers)A measure of complexity within a piece of code.
Recursion - (answers)The process of looping, calling itself in looping.
Functions - (answers)A decomposed part of code that has a specific job to output
or return something
Iteration - (answers)Repeating some part of code over and over
Subroutine - (answers)A decomposed part of problem that *does something*
,2
Data Mining - (answers)The process of collecting data on user habits or requests
Binary Search - (answers)A search algorithm that includes comparing the midpoint
of an array iteratively.
Insertion Sort - (answers)A sorting algorithm that includes going through an array
iteratively comparing each value to every value before that value.
Bubble Sort - (answers)Moving through a list, it compared two elements and
moves on, moving through the array repeatedly.
Quick Sort - (answers)
Merge Sort - (answers)
Global Variable - (answers)
Local Variable - (answers)
Dijkstra's Algorithm - (answers)
Travelling Salesman Algorithm - (answers)
,3
Decomposition - (answers)
Graph Tree - (answers)
Heuristic - (answers)
Pipelining - (answers)
Stack - (answers)
ALU (Arithmetic Logic Unit) - (answers)The part of the CPU where data is
processed and manipulated. Usually arithmetic or logical operations. Allows for
decisions to be made.
Control Unit - (answers)The part of the CPU that manages the execution of
instructions. The control unit fetches an instruction, and decodes it before
executing it by sending 'control signals' to other parts of the computer.
Register - (answers)Tiny stores of extremely fast memory located in the CPU,
normally designed for where data or control information is stored temporarily
when execution is taking place.
, 4
Program Counter (PC) - (answers)A register in the control unit which holds the
address of the next instruction to be executed. When each program is executed,
this number goes up by 1 to signify the next 'fetch' to be at this address in the
RAM.
Accumulator (ACC) - (answers)A special register within the Arithmetic Unit. It is
used to hold the data currently being processed by the CPU. Any data to be
processed is stored temporarily in the accumulator.
Memory Address Register (MAR) - (answers)A register in the CPU that stores the
address of the memory location currently in use. In the fetch phase, this would be
the address of an instruction; in the execute phase, it would be the address of the
data being used.
Memory Data Register (MDR) - (answers)Used to temporarily store data loaded
into the CPU, or written to memory locations. All transfers from memory locations
to the CPU go via the Memory Data Register.
Current Instruction Register (CIR) - (answers)A register in the control unit that
stores the instruction type of the next instruction to be carried out by the
processor. For example, this could contain the number 3, which in LMC is a 'store'
function.
Buses - (answers)A common physical pathway for signals to travel to and from
several components of a computer.
OCR A LEVEL COMPUTER SCIENCE EXAM
| QUESTIONS AND ANSWERS | VERIFIED
AND WELL DETAILED ANSWERS (100%
CORRECT) | LATEST EXAM UPDATE
1 Dimensional Arrays - (answers)A standard list array - one index is needed to
search for something in an array.
2 Dimensional Arrays - (answers)An array with 2 indexes needed to search - for
example a table could be this.
Interception of PseudoCode - (answers)The ability to pick out and explain parts of
code.
Big O' - (answers)A measure of complexity within a piece of code.
Recursion - (answers)The process of looping, calling itself in looping.
Functions - (answers)A decomposed part of code that has a specific job to output
or return something
Iteration - (answers)Repeating some part of code over and over
Subroutine - (answers)A decomposed part of problem that *does something*
,2
Data Mining - (answers)The process of collecting data on user habits or requests
Binary Search - (answers)A search algorithm that includes comparing the midpoint
of an array iteratively.
Insertion Sort - (answers)A sorting algorithm that includes going through an array
iteratively comparing each value to every value before that value.
Bubble Sort - (answers)Moving through a list, it compared two elements and
moves on, moving through the array repeatedly.
Quick Sort - (answers)
Merge Sort - (answers)
Global Variable - (answers)
Local Variable - (answers)
Dijkstra's Algorithm - (answers)
Travelling Salesman Algorithm - (answers)
,3
Decomposition - (answers)
Graph Tree - (answers)
Heuristic - (answers)
Pipelining - (answers)
Stack - (answers)
ALU (Arithmetic Logic Unit) - (answers)The part of the CPU where data is
processed and manipulated. Usually arithmetic or logical operations. Allows for
decisions to be made.
Control Unit - (answers)The part of the CPU that manages the execution of
instructions. The control unit fetches an instruction, and decodes it before
executing it by sending 'control signals' to other parts of the computer.
Register - (answers)Tiny stores of extremely fast memory located in the CPU,
normally designed for where data or control information is stored temporarily
when execution is taking place.
, 4
Program Counter (PC) - (answers)A register in the control unit which holds the
address of the next instruction to be executed. When each program is executed,
this number goes up by 1 to signify the next 'fetch' to be at this address in the
RAM.
Accumulator (ACC) - (answers)A special register within the Arithmetic Unit. It is
used to hold the data currently being processed by the CPU. Any data to be
processed is stored temporarily in the accumulator.
Memory Address Register (MAR) - (answers)A register in the CPU that stores the
address of the memory location currently in use. In the fetch phase, this would be
the address of an instruction; in the execute phase, it would be the address of the
data being used.
Memory Data Register (MDR) - (answers)Used to temporarily store data loaded
into the CPU, or written to memory locations. All transfers from memory locations
to the CPU go via the Memory Data Register.
Current Instruction Register (CIR) - (answers)A register in the control unit that
stores the instruction type of the next instruction to be carried out by the
processor. For example, this could contain the number 3, which in LMC is a 'store'
function.
Buses - (answers)A common physical pathway for signals to travel to and from
several components of a computer.
