The immune system is a complex network of cells, tissues, and organs that work together to defend the body against harmful invaders, such as bacteria, viruses, and other pathogens. It is like the body's own defense system, constantly working to keep us healthy and protected.
When a harmful invader enters the body, such as a virus or bacteria, the immune system kicks into action. The white blood cells and antibodies work together to identify and neutralize the threat. This process can take some time, which is why we may feel unwell when we are sick. However, once the immune system has successfully fought off the invader, it "remembers" it, which helps to provide immunity in the future.
All organisms have structures and systems with separate functions. Students can:
Develop and communicate an evidence-based scientific explanation of the role of different organs or structures that are important for an organism's survival - in both plants and animals