Learn: B1-4 (AQA GCSE Combined Science)

Welcome!Welcome to today's lesson on B1-4, which is all about understanding key biological concepts from cell structure to processes like photosynthesis and respiration. I've tailored this lesson to help strengthen your understanding of the foundational principles in this topic.

What is Cell Biology?Cell biology is the study of cells, the basic building blocks of all living organisms. Cells are the smallest units of life, and understanding their structure and function helps us comprehend how the human body and other organisms work.

Prokaryotic and Eukaryotic CellsThere are two main types of cells: prokaryotic cells (simple cells without a nucleus, like bacteria) and eukaryotic cells (complex cells with a nucleus, like plant and animal cells). Eukaryotic cells are larger, have organelles like mitochondria, and are found in multicellular organisms.

Specialised CellsCells are adapted to carry out specific functions. For example, red blood cells are specialised to carry oxygen, while root hair cells in plants are adapted to absorb water and minerals from the soil.

MicroscopyMicroscopes allow us to see cells and cellular structures that are too small to see with the naked eye. Light microscopes use light and lenses to magnify images, while electron microscopes use electrons for higher magnification and resolution.

DiffusionDiffusion is the movement of particles from an area of higher concentration to an area of lower concentration. It is important for processes like oxygen entering cells and carbon dioxide leaving them during respiration.

Review Time!Great work! You've learned about cell types, specialised cells, microscopy, and diffusion. Let's test your understanding with a few final questions.