What are the four components of blood?
Red blood cells, white blood cells, platelets and plasma.
AQA GCSE Combined Science: Trilogy (8464) — Biology — Higher · 4.2.2.3
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What are the four components of blood?
Red blood cells, white blood cells, platelets and plasma.
What is blood plasma?
The liquid component of blood, which carries blood cells and platelets around the body.
What five types of dissolved substance does blood plasma carry around the body?
Ions, nutrients, urea, hormones and carbon dioxide.
What is the transport role of red blood cells?
They transport oxygen around the body.
What role does haemoglobin play in oxygen transport?
It binds oxygen for transport and releases it where needed.
What features distinguish red blood cells from white blood cells in photomicrographs and diagrams?
Red blood cells are small biconcave discs and lack a nucleus.
What are platelets, and what is their role when a blood vessel is damaged?
Platelets are small fragments carried in blood that help it clot.
How does a blood clot prevent further blood loss?
It seals the damaged area of the blood vessel.
How does a blood clot protect against pathogens?
It reduces their entry into the body.
What is the main function of red blood cells?
To transport oxygen.
How does a red blood cell’s biconcave shape aid oxygen diffusion?
It provides a large surface area and a short diffusion distance.
How does the absence of a nucleus help a red blood cell transport oxygen?
It leaves more space for haemoglobin.
How does flexibility help red blood cells?
It allows them to pass through narrow capillaries.
What is the main function of white blood cells?
To defend the body against pathogens.
How does a phagocyte use its ability to change shape to defend the body?
It surrounds and engulfs pathogens.
What nuclear and cytoplasmic features are typical of neutrophils, a type of phagocyte?
A lobed nucleus and granular cytoplasm.
What nuclear and cytoplasmic features are typical of lymphocytes?
A large, round nucleus with a narrow rim of cytoplasm.
What do some lymphocytes produce to bind to specific pathogens?
Antibodies.