NEET BIOLOGY

Detailed explanation-1: -Researchers often include multiple independent variables in their experiments. The most common approach is the factorial design, in which each level of one independent variable is combined with each level of the others to create all possible conditions.

Detailed explanation-2: -In an experiment, the researcher varies (or manipulates) one or more independent variables. An independent variable must have two or more levels (different values). These levels can reflect either quantitative or qualitative differences in the independent variable.

Detailed explanation-3: -There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.

Detailed explanation-4: -The other variables are called controlled variables because the experiment is designed to keep them at an unchanging value, known as “controlling” a variable. A valid experiment should have only one independent variable.