Each cell of the human body contains two meters of DNA. The whole secret lies in the intricate three-dimensional arrangement that allows DNA strands to be efficiently organized and compacted ...

The capillaries connect the two types of blood vessel and molecules are exchanged between the blood and the cells across their walls. Structure and function of the heart In this Higher Human ...

Examples of multicellular organisms include animals and most species of plants. The following diagram shows the variety of human cell types.