In an experiment, a scientist decides to study the effect of exercise on cholesterol levels in people. he studies two set of people—those who exercise every day for an hour and those who don’t exercise at all. in this case, the statement that people who exercise for an hour may have lower cholesterol levels is . to test this statement, the scientist would measure cholesterol levels in exercisers and non-exercisers. the cholesterol levels would be .

The exercise reduces the levels of the low density lipoproteins or the bad cholesterol. It is found that, the people, who exercise daily have a low level of low density lipoproteins, and an increased level of high density lipoprotein, which is also known as good cholesterol.

Hence, to check whether a person exercises regularly or not, the scientist can determine the cholesterol level, in case, the bad cholesterol is high, then it indicates low physical activity.

In non exercisers the cholesterol level would be high.

In this case, the statement that people who exercise for an hour may have lower cholesterol levels is a hypothesis . To test this statement, the scientist would measure cholesterol levels in exercisers and non-exercisers. The cholesterol levels would be a dependent variable.

Explanation:

Scientific hypotheses, in general, are the premises within a given theory, which can be validated on the basis of a scientific method, contributing to the formulation of new hypotheses. In this experiment the theory says that cholesterol levels between people who exercise and people who do not exercise is different. Within this theory, the statement says that people who exercise for an hour may have lower cholesterol levels, is a hypothesis that will be confirmed or refuted after the experiment.

The dependent variable is summarized in the phenomena or factors explained or identified, because they are influenced or determined by the independent variable. In this experiment the independent variable is the performance (or not) of exercises. Exercise is what influences or determines cholesterol levels in this study. Thus, cholesterol levels are a dependent variable.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.