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Homeostasis | GCE O Level Biology Notes (5090)

Homeostasis is a very important topic in biology (5090) and there are multiple concepts in this topic which you need to learn.  First of all, you should know that what is meant by homeostasis?  The system of a body which is responsible for the maintenance of the internal environment is known as homeostasis .  In other words, it is the ability to maintain a stable state that continues despite the changes outside. This system ensures the survival of all species from plants to animals.  This was all about the introduction of this topic. Now, let's move into further details and learn about some other topic as well.  Negative feedback:  To maintain a constant internal environment, a significant principle known as negative feedback occurs. In other words, it is the principle on which homeostasis works.  In biological systems, negative feedback  (a regulatory mechanism) is a type of regulation that occurs when a specific stimulus (change) is detected.  For instance, when the temperature o

Turning Effect of Forces | GCE O Level Physics (5054)

The turning effect of forces is a very important topic in Physics and there are multiple topics in this chapter which you need to learn.  First of all, you should know that a force may cause an object to rotate (clockwise or anticlockwise) around its pivot (a central point or shaft where an object turns).  This is known as the turning effect of a force or the moment of the force.  The turning effect of a force is mainly dependent upon two factors which are: The magnitude of the force The perpendicular distance from the pivot to the line of action of the force The moment of a force (torque):  The torque (moment of a force) is the product of the force and the perpendicular distance from the line of action of the force to the pivot (central point).  In terms of an equation, this can be summed up as: moment of a force = force (F) x distance (d) M = F x d The SI unit for torque (moment of a force) is newton metre (N m) because the symbol for force is newton and the symbol of distance is