Friction is a force that works against motion. While walking, friction helps us maintain our stability and prevents us from slipping. Friction also works the same way with cars and vehicles in general, preventing them from skidding and helping them stop when the brakes are applied. We also need friction to make a fire.
<span>Growth harmones are released from pitutary gland in to the blood stream. This harmone promotes growth in children till they grow upto 15-18 years. Then this harmone stops. The excess secretion of this harmone leads to over height that is Gigantism. the dificiency of growth harmones are leads to shortness i.e. dwarfinism. The growth harmones secretes equally in both boys and girls. It secretes in hypothalamus of the brain</span>
There are 7 unifying themes in biology
1.Cell structure and function
2.Reproduction
3.Metabolism
4.Homeostasis
5.Heredity
6.Evolution
7.Interdependence