Who this is for: Cambridge IGCSE Biology (0610) students who want blood composition — plasma, red blood cells, white blood cells and platelets — to become a reliable source of marks instead of a vague list mixed up with blood vessel structure.
What query it owns: how to understand and revise blood in Cambridge IGCSE Biology (0610).
Why this is safe: this page owns the blood revision-guide angle, while Tutopiya’s Blood subtopic page owns the learning resource and the free Blood quiz owns the practice.

Blood is tested in almost every Cambridge IGCSE Biology (0610) Transport in animals paper. Whenever a question asks you to state the function of red blood cells, explain how white blood cells defend the body, or describe the role of platelets in clotting — examiners expect precise structure–function links. This guide explains exactly what blood covers, how to handle the question types that actually appear, and where to practise each skill.

Key takeaways

• Blood is a tissue made of plasma (liquid) and formed elements: red blood cells, white blood cells and platelets.
• Red blood cells transport oxygen — biconcave shape, no nucleus, contain haemoglobin.
• White blood cells defend against pathogens — phagocytosis and antibody production.
• Platelets trigger blood clotting to prevent blood loss and entry of pathogens.

What is blood in Cambridge IGCSE Biology?

Blood is a connective tissue that transports substances around the body in the Transport in animals unit of Cambridge IGCSE Biology (0610). Plasma is the pale yellow liquid carrying dissolved glucose, amino acids, urea, carbon dioxide, hormones and antibodies. Red blood cells, white blood cells and platelets are suspended in plasma. Each component has a structure adapted to its function.

Read the full explanation on Tutopiya’s Blood subtopic page before you attempt questions.

The core ideas you must master

Component	Structure	Function	Exam signal
Plasma	Liquid matrix	Transport dissolved substances	”What is carried in plasma?”
Red blood cells	Biconcave, no nucleus, haemoglobin	Oxygen transport	”Adaptations of RBCs”
White blood cells	Larger, nucleus, can change shape	Defence / immunity	”Phagocytosis”
Platelets	Cell fragments	Blood clotting	”Prevent blood loss”

How to answer blood questions — step by step

1. Identify which component the question targets — plasma, RBC, WBC or platelets.
2. State structure — shape, nucleus present or absent, special features.
3. Link structure to function — biconcave = large SA for oxygen diffusion.
4. Name the process — phagocytosis for some WBCs; clotting for platelets.
5. For compare questions — tabulate all four components.
6. Check you have not described blood vessels — arteries and veins are a separate subtopic.

Test yourself with the free Blood quiz once definitions stick.

Blood components in past-paper wording: command words that matter

Command word	What the question wants	Typical blood stem
State	Short factual answer	”State the function of haemoglobin.”
Describe	Features, no why	”Describe the structure of a red blood cell.”
Explain	Reason or mechanism	”Explain how white blood cells defend the body.”
Compare	Similarities and differences	”Compare red and white blood cells.”

Worked exam-style stems (how to answer the wording)

1. “Describe the structure of a red blood cell and relate it to its function.” Biconcave disc shape → large surface area; no nucleus → more room for haemoglobin; haemoglobin binds oxygen. Reward: each adaptation linked to oxygen transport.
2. “Explain the role of platelets in blood clotting.” Platelets collect at wound → trigger clotting cascade → fibrin mesh forms → seals wound, prevents blood loss and pathogen entry. Reward: clotting + prevention of blood loss.
3. “State two substances transported in blood plasma.” Accept glucose, amino acids, urea, CO₂, hormones, antibodies. Reward: two correct named substances.

Work the full set on the Transport in animals mini learning course and the Blood quiz.

How blood connects to the rest of Transport in animals (0610)

Blood flows through Blood Vessels pumped by the Heart in a Circulatory System. When you are ready to mix topics, the Cambridge IGCSE Biology resource hub links every Transport in animals subtopic.

Common mistakes students make

• Saying red blood cells have a nucleus — they do not at maturity.
• Confusing platelets with white blood cells.
• Describing phagocytosis for red blood cells — that is a white blood cell process.
• Listing blood components without linking structure to function.
• Forgetting plasma transports urea and CO₂ as well as nutrients.

When you need more support

If blood component questions keep tripping you up, work through the Blood quiz to pinpoint the gap, then get focused help from a Cambridge IGCSE Biology tutor.

Frequently asked questions

Is blood hard in Cambridge IGCSE Biology? The components are straightforward. Marks are lost when students omit adaptations or confuse cell types.

What is the quickest way to describe a red blood cell? Biconcave, no nucleus, contains haemoglobin — adapted for oxygen transport.

Do I need to know all types of white blood cell? Know that white blood cells defend the body by phagocytosis and antibody production; naming lymphocytes and phagocytes is useful.

How do I revise blood effectively? Read the subtopic notes, practise describe and explain stems, then take the Blood quiz.

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