This is mainly water.: In the model, this is the water. Mitochondria close mitochondriaTiny parts of cells floating in the cytoplasm where energy is released from glucose. The glucose comes from food.

Prometaphase is an extremely dynamic part of the cell cycle. Microtubules rapidly assemble and disassemble as they grow out of the centrosomes, seeking out attachment sites at chromosome ...

The growth of new segments (body parts) in marine worms is controlled by a special growth zone, in which special stem cells are located. New segments then emerge by the division of these cells.