Notes on AQA GCSE Biology Paper One Overview

Introduction

• Comprehensive video covering AQA GCSE Biology Paper One.
• Video includes key concepts, topic summaries, examiners' tips, and questions/answers.

Eukaryotic vs. Prokaryotic Cells

Eukaryotic Cells (Animals and Plants)

• Animal Cells: Features include cytoplasm, cell membrane, mitochondria, nucleus, and ribosomes.
• Plant Cells: Similar to animal cells but also have a cell wall, permanent vacuole, and chloroplasts.
• Chloroplasts contain chlorophyll for photosynthesis.

Prokaryotic Cells (Bacteria)

• Smaller than eukaryotic cells.
• Contains cytoplasm, cell membrane, and sometimes a cell wall.
• Genetic material not in a nucleus, may have plasmids.

Cell Specialization and Organization

• Hierarchy: Cells → Tissues → Organs → Organ Systems → Organism.
• Examples of Specialized Cells: Sperm cell, muscle cell, nerve cell.
• Plant specialized cells include xylem and phloem.

Microscopes

• Light Microscopes: Use light, show live samples, magnify up to 2000x.
• Electron Microscopes: Use electron beams, higher magnification and resolution, show detailed cell structures.

Cell Cycle and Mitosis

• Purpose: Growth, repair, and development.
• Stages: Cell growth, DNA replication, cell division (mitosis).

Stem Cells

• Types: Embryonic (pluripotent), adult (limited differentiation), plant meristems.
• Uses: Treat diseases, research.
• Ethical Considerations: Embryo use, cloning techniques.

Transport Across Cell Membranes

Diffusion

• Movement from high to low concentration.
• Factors: concentration gradient, temperature, surface area.

Osmosis

• Diffusion of water across a semi-permeable membrane.
• Effects on plant tissues (e.g., potato experiments).

Active Transport

• Movement against concentration gradient, requires energy.
• Examples: Root hair cells, nutrient absorption in the gut.

Organization in Biology

• Systems Covered: Digestive, circulatory, respiratory, plant transport.
• Digestive System: Organs involved, enzymes (carbohydrases, proteases, lipases).
• Circulatory System: Heart structure and blood flow, blood vessels, blood components.
• Respiratory System: Gas exchange in the alveoli, adaptations for efficient exchange.

Health and Disease

Non-Communicable Diseases

• Risk factors: diet, lifestyle, environmental.
• Cardiovascular disease, cancer, diabetes.

Cancer

• Uncontrolled cell growth, benign vs. malignant tumors.
• Risk factors: genetic, environmental.

Plant Biology

• Photosynthesis: Light-dependent process to produce glucose.
• Factors Affecting Rate: Light intensity, carbon dioxide concentration, temperature, chlorophyll.

Respiration

• Types: Aerobic (with oxygen), anaerobic (without oxygen).
• Equations: Glucose + Oxygen → Carbon dioxide + Water (+ Energy).

Response to Exercise

• Increased demand for energy.
• Body Responses: Increased heart/breathing rate, removal of lactic acid.

Drug Development and Antibiotics

• Discovery from natural sources, clinical trials.
• Antibiotic resistance, importance of completing courses.

Advanced Topics

• Monoclonal Antibodies: Production, uses, advantages/disadvantages.
• Plant Detections: Disease symptoms, diagnostic techniques.