Blood
A liquid tissue that carries oxygen, food, waste and heat. It has red cells, white cells, platelets and plasma.
Last updated
Analogy
A delivery service with many types of van.
In practice
Red blood cells carry oxygen. Platelets help blood clot at a cut.
Practice
Flashcards
- What do red blood cells carry?Oxygen, in a substance called haemoglobin.
Questions people ask
What do white blood cells do?
White blood cells defend the body against disease. Some engulf and digest pathogens, called phagocytosis. Others make antibodies that lock onto pathogens, or make antitoxins that neutralise poisons. They are part of the immune system, and the body makes more of them when you are ill.
Why do red blood cells have no nucleus?
Without a nucleus, there is more room inside the cell for haemoglobin, the red pigment that carries oxygen. The cell also has a flattened disc shape that gives a large surface area for taking in oxygen. The trade-off is that red blood cells cannot divide and live only about four months.