7; a heptagon is a seven-sided polygon.

It’s 11,638

Evapotranspiration is the sum of water released from plant transpiration and water released from evaporation from the Earth’s land and ocean surface to the atmosphere. I.e. evapotranspiration = transpiration + evaporation

The ribosome is a complex molecular machine, found within all living cells, that serves at the site of biological protein synthesis. Ribosomes link amino acids together in the order specified by messenger RNA molecules.

Mechanical digestion refers to the breakdown of food into smaller parts by means of a mechanical process i.e. by physically breaking the food apart into smaller bits. Mechanical digestion begins in the mouth where the teeth chew apart the piece of bread you have just eaten. This has the advantage of increasing the foods surface area which allows enzymes in the stomach to break down the food chemic... more

The kidney belongs to the urinary system and is therefore involved in the production of urine. In easy terms, its function is to regulate the contents of the blood, its acidity and its volume. It does so by finely balancing out the amount of water that is excreted in the urine. It also filters the blood to get rid of any unwanted and potentially toxic waste products (e.g. urea). The liver is par... more