Study guides

Selective breeding: Selective breeding can lead to ‘inbreeding’ where some breeds are particularly prone to disease or inherited defects.

AQA·GCSE

8464

Selective breeding: Selective breeding involves choosing parents with the desired characteristic from a mixed population. They are bred together. From the offspring those with the desired characteristic are bred together. This continues over many generations until all the offspring show the desired characteristic.

AQA·GCSE

8464

Selective breeding: Students should be able to explain the impact of selective breeding of food plants and domesticated animals.

AQA·GCSE

8464

Selective breeding: The characteristic can be chosen for usefulness or appearance:

AQA·GCSE

8464

Self, Death and the Afterlife

OCR·A-Level

This study guide delves into the OCR A-Level Religious Studies topic of Self, Death and the Afterlife, a cornerstone of the Philosophy of Religion paper. It critically examines the mind-body problem, contrasting dualist and materialist perspectives, and evaluates the logical possibility of post-mortem existence, providing candidates with the analytical tools to excel in AO2-heavy questions."

Sensory evaluation

OCR·GCSE

Unlock top marks in your OCR GCSE Food exam by mastering the science of sensory evaluation. This guide demystifies how we perceive food, moving beyond simple 'taste' to explore the crucial interplay of aroma, texture, and appearance that examiners want you to analyse with scientific precision.

Separate chemistry 1

Pearson Edexcel·GCSE

Pearson-GCSE-Chemistry

Master the principles of chemical cells and hydrogen-oxygen fuel cells. This topic is essential for understanding modern clean energy technology and frequently appears in 4-6 mark evaluation questions.

Separate chemistry 2

Pearson Edexcel·GCSE

Pearson-GCSE-Chemistry

Master the fundamentals of hydrocarbons with this essential guide to alkanes and alkenes. You'll learn to draw structural formulas, distinguish saturated from unsaturated molecules, and ace the classic bromine water test—key skills that frequently appear in 4-6 mark exam questions.

Sequences

OCR·GCSE

Sequences in OCR GCSE Further Mathematics extend beyond standard GCSE, requiring mastery of quadratic sequences, geometric progressions, limiting values, and recurrence relations. This topic is essential for top grades, testing algebraic rigour, pattern recognition, and the ability to determine long-term behaviour of mathematical series.

Sequences and Series

WJEC·A-Level

603/1977/X

Sequences and series convert patterns into precise formulas, totals and models, making them a reliable source of method marks in WJEC A-Level Mathematics. Master the difference-versus-ratio decision, convergence check and binomial validity condition, and even multi-step questions become a sequence of manageable decisions.

Sequences: deduce expressions to calculate the nth term of linear sequences

AQA·GCSE

8300

Sequences: generate terms of a sequence from either a term-to-term or a position-to-term rule

AQA·GCSE

8300

Sequences: including Fibonacci-type sequences, quadratic sequences, and simple geometric progressions (rⁿ where n is an integer and r is a rational number > 0)

AQA·GCSE

8300

Sequences: including other sequences including where r is a surd (Higher tier only)

AQA·GCSE

8300

A multiplier can be irrational while the pattern stays beautifully simple. Master exact surd arithmetic, count the jumps correctly and turn unfamiliar Higher-tier sequences into clear, mark-worthy solutions.

Sequences: including quadratic sequences (Higher tier only)

AQA·GCSE

8300

A quadratic sequence hides a surprisingly simple rule: constant second differences reveal its n² component. Learn to rebuild the full nth term, handle negative and fractional coefficients, and turn membership questions into marks with clear algebra. The complete resource is available as a [downloadable JSON study guide](/home/ubuntu/study_guide_sequences/quadratic_sequences_study_guide.json).

Sequences: recognise and use sequences of triangular, square and cube numbers and simple arithmetic progressions

AQA·GCSE

8300

Series and parallel circuits: calculate the currents, potential differences and resistances in dc series circuits

AQA·GCSE

8464

Series and parallel circuits: describe the difference between series and parallel circuits

AQA·GCSE

8464

Series and parallel circuits: explain qualitatively why adding resistors in series increases the total resistance whilst adding resistors in parallel decreases the total resistance

AQA·GCSE

8464

Series and parallel circuits: explain the design and use of dc series circuits for measurement and testing purposes

AQA·GCSE

8464

Series and parallel circuits: For components connected in parallel:

AQA·GCSE

8464

Series and parallel circuits: For components connected in series:

AQA·GCSE

8464

Series and parallel circuits: resistance, R, in ohms, Ω

AQA·GCSE

8464

Series and parallel circuits: Rtotal = R₁ + R₂

AQA·GCSE

8464

Series and parallel circuits: solve problems for circuits which include resistors in series using the concept of equivalent resistance.

AQA·GCSE

8464

Series and parallel circuits: the potential difference across each component is the same

AQA·GCSE

8464

Series and parallel circuits: the total current through the whole circuit is the sum of the currents through the separate components

AQA·GCSE

8464

Series and parallel circuits: the total potential difference of the power supply is shared between the components

AQA·GCSE

8464

Series and parallel circuits: the total resistance of two components is the sum of the resistance of each component.

AQA·GCSE

8464

Series and parallel circuits: the total resistance of two resistors is less than the resistance of the smallest individual resistor.

AQA·GCSE

8464