Science is a investigation process
When levels decrease, the parathyroid releases hormones.
1) Are they reliable?
2) Are they relevant?
3) Are they recent?
4) Are they sound resources?
5) Are they a primary source?
6) Are they a secondary source?
A sample is a random, unbiased selection out of a larger group. An independent variable is one that is changed as to see how it will affect the dependent variable in an experiment.
Hope that helped.
