Blood Cell Structure and Function Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Examine the structure of different blood cells and explain how each type is perfectly adapted to carry out its specific function in the body.

• Identify the three main types of blood cells from photographs or diagrams
• Explain how red blood cells are adapted for oxygen transport
• Describe the structure and function of white blood cells in immune defence
• Compare the adaptations of different blood cell types to their specific roles

Key ideas to keep in view

Use this lesson to stay inside B2.2 The challenges of size while connecting the detail back to the wider B2: Scaling up topic.

• B2: Scaling up
• B2.2 The challenges of size
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Blood Cell Structure and Function before testing yourself from memory.

• 1. Blood Cell Recognition - The Visual Guide
• Your blood contains three distinct types of cells, each with a unique shape that reveals its job. Under a microscope, you'll see red discs, larger irregular blobs, and tiny fragments - but there's method in this apparent chaos.
• Red blood cells look like doughnuts that someone's squashed flat - this biconcave shape isn't random. White blood cells appear as larger, often irregular shapes with dark centres (their nuclei). Platelets look like tiny fragments scattered between the larger cells.
• 2. Red Blood Cells - The Oxygen Delivery Service
• A biconcave disc-shaped cell specialised for oxygen transport. Contains haemoglobin protein but lacks a nucleus and organelles.
• Red blood cells are the ultimate example of 'form follows function'. Every feature of their structure serves one purpose: maximum oxygen transport efficiency.
• The biconcave shape increases surface area for gas exchange while keeping the cell flexible enough to squeeze through tiny capillaries. No nucleus means more space for haemoglobin - the iron-containing protein that actually carries the oxygen.
• Exam depth extension: In blood cell structure and function, connect blood cell recognition - the visual guide to red blood cells - the oxygen delivery service using clear cause-and-effect statements. When you explain biological processes, include what changes, why it changes, and the consequence for cells, organisms...
• 3. White Blood Cells - The Body's Defence Force
• White blood cells are your immune system's soldiers, but they're not all identical. Think of them as different military units - some patrol and destroy invaders directly, others coordinate the attack.

Continue through the topic

Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.