Answer:
In a fair test two or more things are compared. In order for a test to be fair or scientifically sound, children are required to ensure only one thing (this is called a variable) is changed.
For example, if testing which material is the most waterproof by pouring liquid onto a selection of different materials, in a fair test only the type of material (the component you are testing) should be changed. Therefore all other elements (the type of liquid used, the amount of liquid used, the distance the liquid is poured from, the speed at which it is poured and the size of the material) must remain the same each time the test is carried out. It would be unfair or an unscientific test if, for example, 1000ml of water were poured onto a piece of foil and 2ml of milk poured onto a piece of foam – you would not be able to fairly compare the materials.
hope this will help you!!!.....
<span>1) Receptors are linked with sensory neurons that send any signals that the receptors pick up to the brain. If the signal requires some kind of response to maintain homeostasis, signals travel through motor neurons to effectors.</span>
<span>2) The organ that controls the regulation of body temperature is the hypothalamus while the process that allows us to maintain our core temperature is referred as thermoregulation.</span>
3) Controlling blood sugar levels with insulin is a negative feedback mechanism. Receptors in the body sense when blood sugar levels rise. To deal with that, the pancreas pumps insulin into the blood to lower it. Blood clotting is a positive feedback mechanism where platelets start to clump around an injury in a blood vessel and release chemicals that bring more platelets that end up doing the same thing to form a clot.
Biofuel, which is chemical energy taken from biodegraded material.
