These are red blood cells (erythrocytes). Their design is a product of evolution. They use haemoglobin to transport oxygen from the lungs to tissues, and transport carbon dioxide from tissues to the lungs. Each cell is between 6 and 8 micrometers wide and typically lasts for 120 days. The blood cells are transported in blood plasma which is a fluid pumped by the heart.
This is a cutaway diagram of a respirocyte. Their design is a product of intelligence. Respirocytes also transport oxygen from the lungs to tissues, and transport carbon dioxide from tissues to the lungs. Each device is 1 micrometer wide sapphire coated sphere with an expected lifespan of 20 years. The respirocyte includes a glucose motor and is independently self propelled. A functioning heart is not necessary.
Okay, is everyone clear about the difference between intelligent design and evolution now? Good.