Identical twins have identical DNA profiles, because they develop from a single fertilized egg that splits into two.

Your DNA has 23 pairs of chromosomes, one set inherited from your father, the other from your mother.

There are 20 times more bacteria than cells in your body.

Sweat is a natural air conditioning to cool you down. The sweat doesn't smell — it's the bacteria munching on it that smell!

The human heart beats about 40 million times a year.

Bad breath is caused by millions of tiny critters called bacteria which live, eat, reproduce, poo and die in your mouth.