Which Element Can Be Found in the Center of Each

question 56

Multiple Choice

Which element can be found in the center of each heme ring that makes up the protein hemoglobin?

• A) iron
• B) calcium
• C) helium
• D) mercury
• E) sodium

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Definitions:

Experimental Approach

A research method involving the manipulation of variables to observe and measure the effects on subjects in a controlled setting.

Manipulation of Variable

The process in experimental research of changing one variable to determine if changes in one variable cause changes in another variable.

Confounds

Variables that obscure the clear understanding of the relationship between different variables in a study, due to their intertwined effects.

Dependent Variable

In scientific research, the variable that is measured to see how it is affected by changes in another variable (the independent variable).