Red blood cell Carry oxygen. Contain haemoglobin (rich in iron) to carry oxygen. Biconcave shape to provide a large surface area for the diffusion of oxygen. No nucleus to provide more space for ...

blood a pump (the heart) to push the blood around the body a system of tubes to contain the ... It consists of four main components: ...

Veins between two capillary networks are portal systems. Closed circulatory system, but fluid constituents of blood leak out of capillaries and return to the heart by the second component of the ...

Aminoacyl tRNA synthetases picked up new protein domains that participate in vasculature formation around the same time that organisms evolved key adaptations in the circulatory system. Amber Dance is ...