Cells and Organisation Understanding the fundamental unit of life, the cell , is crucial in GCSE Biology. Cells can be classified into two main types: prokaryot...
Understanding the fundamental unit of life, the cell, is crucial in GCSE Biology. Cells can be classified into two main types: prokaryotic and eukaryotic.
Prokaryotic cells, such as bacteria, are generally smaller and simpler. They lack a nucleus and membrane-bound organelles. In contrast, eukaryotic cells, which make up plants and animals, contain a defined nucleus and various organelles.
Cells can become specialised to perform specific functions. For example, red blood cells are adapted to transport oxygen, while neurons are structured for signal transmission.
Understanding microscopy is essential for studying cells. Light microscopes allow us to see cells in color, while electron microscopes provide higher magnification and resolution, revealing detailed structures.
Cell division occurs through mitosis, ensuring that each daughter cell receives an identical set of chromosomes. The cell cycle consists of stages: interphase, mitosis, and cytokinesis.
Stem cells are undifferentiated cells with the potential to develop into various cell types. They play a significant role in growth and repair.
Cells transport substances across their membranes through various processes:
In multicellular organisms, cells are organised into tissues, organs, and systems:
Key human systems include:
Understanding diseases such as coronary heart disease (CHD) and cancer is vital, as they affect the organisation and function of cells and tissues.
In plants, organisation includes:
In summary, the study of cells and their organisation provides insight into the complexity of life and the interdependence of various biological systems.