AQA AS and A-level Biology Specification Notes

1 Introduction

1.1 Why choose AQA for AS and A-level Biology
  • AQA involved over a thousand teachers in the development of these specifications ensuring relevance and engagement in both classroom and real-world contexts.
  • Specifications allow for freedom in teaching methods tailored to students' needs.
  • University consultations ensure the curriculum develops requisite skills for future biological science and medical courses.
  • Support for practical skills, as Biology is fundamentally experimental, with numerous opportunities to integrate practical experiences to connect theory with reality.
  • AS and A-level components are co-teachable, providing a seamless transition from GCSE content.
  • Assessment design ensures clarity, familiarity, and accessibility to reward knowledge.

      Key features of assessment include:
      - Accessible assessments catering to varied abilities.
      - A choice of essay questions for holistic integration of knowledge (A-level only).
1.2 Support and resources to help you teach
  • A plethora of resources are offered to assist in effective course delivery, including:
      - Additional practice papers.
      - Planning guides and co-teaching materials.
      - AQA-approved student textbooks tailored by experienced examiners.
      - Detailed lesson plans on key topics.
      - Teacher training and subject expertise courses.
  • Exam preparation support includes access to past papers, mark schemes, examiner reports, sample papers, and exemplar answers.
  • Enhanced Results Analysis (ERA) tool for analyzing student performance trends.
  • Professional development courses addressing diverse needs and ensuring compliance with educational standards.

2 Specification at a glance

2.1 Subject content
Core content topics:
  1. Biological molecules
  2. Cells
  3. Organisms exchange substances with their environment
  4. Genetic information, variation and relationships between organisms
  5. Energy transfers in and between organisms (A-level only)
  6. Organisms respond to changes in their internal and external environments (A-level only)
  7. Genetics, populations, evolution, and ecosystems (A-level only)
  8. The control of gene expression (A-level only)
2.2 AS Assessments

Paper 1

  • Content: Topics 1–4, including relevant practical skills.
  • Written exam: 1 hour 30 minutes.
  • Total marks: 75.
  • 50% of AS.
      - 65 marks: short answer questions.
      - 10 marks: comprehension.

Paper 2

  • Content: Topics 1–4, including relevant practical skills.
  • Written exam: 1 hour 30 minutes.
  • Total marks: 75.
  • 50% of AS.
      - 65 marks: short answer questions.
      - 10 marks: extended response.
2.3 A-level Assessments

Paper 1

  • Content: Topics 1–4, including practical skills.
  • Written exam: 2 hours.
  • Total marks: 91.
  • 35% of A-level.
      - 76 marks: short and long answer questions.
      - 15 marks: extended response.

Paper 2

  • Content: Topics 5–8, including practical skills.
  • Written exam: 2 hours.
  • Total marks: 91.
  • 35% of A-level.
      - 76 marks: short and long answer questions.
      - 15 marks: comprehension.

Paper 3

  • Content: Topics 1–8, including practical skills.
  • Written exam: 2 hours.
  • Total marks: 78.
  • 30% of A-level.
      - 38 marks: structured questions (including practical techniques).
      - 15 marks: data critical analysis.
      - 25 marks: essay (choice of two titles).

3 Subject content

General Overview
  • Sections 1-4 are covered in the first year, also constituting AS content. Each section begins with a broad overview to contextualize the material, promoting a comprehensive understanding.
  • Content is structured in two columns:
      - Left Column: Specification content assessed via written papers.
      - Right Column: Opportunities for skills related to the coursework (skills in biology represented as MS, AT, and PS).
3.1 Biological molecules
  • All living organisms share common chemistry, indicating evolutionary connections. Key groups of carbon-based compounds include:
      - Carbohydrates: Serve as respiratory substrates and form structural elements in membranes.
      - Lipids: Function in membranes and energy storage.
      - Proteins: Serve as enzymes, messengers, structural components.
      - Nucleic acids: Carry genetic information, essential for protein synthesis.
      - Water: Crucial as a solvent and participant in metabolic reactions.
3.1.1 Monomers and Polymers
  • Monomers are smaller units (e.g., monosaccharides, amino acids).
  • Polymers consist of repeating monomers.
      - Condensation Reaction: Joins two molecules, releasing water.
      - Hydrolysis Reaction: Splits molecules, using water.
3.1.2 Carbohydrates
  • Monosaccharides include glucose (two isomers: α-glucose, β-glucose), disaccharides such as maltose (two glucose), sucrose (glucose + fructose), and lactose (glucose + galactose) form from condensation reactions.
  • Polysaccharides:
      - Glycogen and Starch: Formed from α-glucose.
      - Cellulose: Formed from β-glucose.
  • Biochemical tests:
      - Benedict’s solution for reducing and non-reducing sugars.
      - Iodine test for starch.
3.1.3 Lipids
  • Two main types: triglycerides and phospholipids.
  • Triglycerides: Formed from glycerol and three fatty acids.
  • Phospholipid structure includes a phosphate group. The distinction between saturated and unsaturated fatty acids is highlighted.
  • Emulsion Test: Detects lipids.
3.1.4 Proteins

General Properties

  • Proteins are made of amino acids, with a general structure comprising amine group (NH2), carboxyl group (COOH), and a variable side chain (R).
      - Dipeptides form from two amino acids, while polypeptides consist of many.
      - Biuret Test: Identifies proteins.
      - The relationship among primary, secondary, tertiary, and quaternary structures exemplifies function.

Enzymes

  • Enzymes lower activation energy and have specific shapes allowing substrate binding, relating to their structure.
  • Affecting factors on enzyme activity:
      - Enzyme concentration, substrate concentration, pH, and temperature.
3.2 Cells
  • All life exists as cells, demonstrating a common structure and function. Cell theory and differences between eukaryotic cells (with organelles) and prokaryotic cells (without organelles) are key concepts.
3.2.1 Cell Structure

Eukaryotic Cells

  • Structures include cell membrane, nucleus, ribosomes, mitochondria, and organelles like Golgi apparatus, lysosomes, and chloroplasts.
  • Cellular specialization leads to tissue, organ, and system formation in multicellular organisms.
3.2.2 Prokaryotic Cells and Viruses
  • Key differences include the absence of membrane-bound organelles and a circular DNA molecule. Viruses are acellular entities with a simpler structure.
3.3 Organisms exchange substances with their environment
  • The importance of exchange surfaces in cellular metabolism is emphasized, alongside mechanisms of mass transport.
3.4 Genetic information, variation, and relationship between organisms
  • Genetic diversity and evolution concepts are intertwined, focusing on mutations, natural selection, and speciation processes.

4 Scheme of assessment

  • Assessment structures for AS and A-level, defining examination formats and methodologies to gauge student understanding across different themes, alongside practical skills integration.
  • Definitions and explanations of assessment objectives detailing what students are expected to demonstrate during assessments.

5 General administration

  • Guidelines for administration, entries, grading, and support offered to both teachers and students, ensuring clarity on the qualifications and processes.

6 Mathematical requirements and exemplifications

  • Mathematical skills integrated into biology understanding (such as ratios, probability, graph construction, and data interpretation).

7 AS practical assessment

  • Emphasis on the role of practical work in biology education. A detailed list of apparatus and techniques expected to be mastered and practicals to be conducted.

8 A-level practical assessment

  • Distinction between written exam assessments and practical skills endorsement, outlining essential practicals required for comprehensive biological understanding.

Key Terminology

  • Polymers: Large molecules formed by monomers.
  • Enzyme: Biological catalysts that speed up reactions.
  • Cell Theory: Fundamental concept stating that all living organisms are composed of cells.
  • Mutations: Changes in DNA sequence that may affect genetic traits.