Constant Variables?

Question

again im exploiting yahoo answers to sound smart in my coursework... I need to list variables that I cna keep the same in my coursework. I have temperature and time so far..the experiment is looking at the rates of reaction of different sugars in yeast, were using a respirometer.

Are there any smart people out there who want to lend there smartness to me??? :)

Answer 1

In an experimental design, the independent variable (argument of the function) is the variable that is manipulated or selected by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). In such an experiment, an attempt is made to find evidence that the values of the independent variable determine the values of the dependent variable (that which is being measured). The independent variable can be changed as required, and its values do not represent a problem requiring explanation in an analysis, but are taken simply as given.

More generally, the independent variable is the thing that one actively controls/changes, while the dependent variable is the thing that changes as a result. In other words, the independent variable is the “presumed cause”, while the dependent variable is the “presumed effect” of the independent variable.

The independent variable is also called the manipulated variable, predictor variable or exposure variable.

In experimental design, a dependent variable (also known as response variable, responding variable or regressand) is a factor whose values in different treatment conditions are compared. That is, the experimenter is interested in determining if the value of the dependent variable varies when the values of another variable – the independent variable – are varied, and by how much. In simple terms, the independent variable is said to cause an apparent change in, or simply affect, the dependent variable. In analysis, researchers usually want to explain why the dependent variable has a certain value. In research, the values of a dependent variable in different settings are usually compared.

Other terms for the dependent variable are y-variable, outcome variable and response variable

Answer 2

Sugars react with yeast to yield alcohol and carbon dioxide, among other things. So what could you change to affect the end products?

The amount of oxygen. The light. The temperature. The amount of yeast. The amount of sugar. The amount of water. The pH or acidity.

Answer 3

constant pressure
constant velocity
constant weight
constant force
constant rpm
and the list goes on.