Organisation and Health

This section of the AQA Combined Science checklist 2024 delves into the organization of cells into tissues, organs, and organ systems, with a particular focus on the digestive, circulatory, and respiratory systems. It also covers important health issues and non-communicable diseases.

The digestive system is explored in detail, with emphasis on the role of enzymes in breaking down food molecules. Students are expected to understand how factors like temperature and pH affect enzyme activity, and be familiar with practical investigations involving enzymes.

Definition: Enzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the process.

The circulatory system is another key topic, covering the structure and function of blood vessels, heart, and blood components. Students should be able to identify various parts of the heart and understand how its structure relates to its function in pumping blood throughout the body.

Vocabulary: The pulmonary artery carries deoxygenated blood from the heart to the lungs, while the pulmonary vein returns oxygenated blood from the lungs to the heart.

Respiratory system structure and function are also covered, with students expected to understand how the lungs are adapted for efficient gas exchange. The alveoli and surrounding capillary network are highlighted as crucial for this process.

Example: The large surface area and thin walls of alveoli allow for rapid diffusion of oxygen into the bloodstream and carbon dioxide out of it.

Health issues, particularly coronary heart disease (CHD), are discussed in detail. Students should understand the causes of CHD and various treatment options, including stents, statins, and heart transplants.

The section concludes with an overview of non-communicable diseases and the impact of lifestyle factors on health. Students are expected to link factors such as diet, alcohol consumption, and smoking to various diseases, including cancer, diabetes, and lung disease.

Highlight: The AQA GCSE Biology Paper 1 Checklist emphasizes the importance of understanding the difference between benign and malignant tumors in the context of cancer.

Cell Biology

This section of the AQA Combined Science specification focuses on the fundamental building blocks of life - cells. It covers essential topics in cell biology that form the foundation for understanding more complex biological processes.

The content begins with cell structure, exploring the various organelles found in eukaryotic and prokaryotic cells. Students are expected to understand how these structures relate to their functions within the cell. For example, mitochondria are crucial for energy production, while chloroplasts enable photosynthesis in plant cells.

Microscopy is another key area, with students learning how to use light microscopes and calculate magnification. The differences between light and electron microscopes are also covered, highlighting the increased resolution and magnification capabilities of electron microscopes.

Vocabulary: Eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells lack these features.

Cell division, particularly mitosis, is explored in detail. Students should be able to describe the stages of mitosis and understand its importance in growth, repair, and asexual reproduction. The role of stem cells in embryos, adult animals, and plant meristems is also discussed.

Example: Stem cells in the bone marrow can differentiate into various types of blood cells, demonstrating their importance in tissue regeneration and maintenance.

The section concludes with an in-depth look at transport processes in cells. Diffusion, active transport, and osmosis are all covered, with students expected to understand the factors affecting these processes and provide relevant examples in plants and animals.

Highlight: The AQA Combined Science Biology paper 1 checklist emphasizes the importance of understanding practical skills, such as investigating the effect of sugar solution concentration on plant tissue mass through osmosis.