In the following scenarios, identify the independent variable, and the dependent variable. 1. Endurance in high altitude mountain climbers with and without the use of supplemental O2.
a. Independent Variable:
b. Dependent Variable:
2. Weight loss in subjects eating low carbohydrate diets.
a. Independent Variable:
b. Dependent Variable:
3. The number of hours spent studying biology each week and grades earned on biology exams.
a. Independent Variable:
b. Dependent Variable:
Suggest a control group for each of the following experiments.
4. Cancer rates in students who smoke cigarettes are closely monitored over a 5-year period.
Control Group:
5. Weightlifters are given 400 mg of creatine phosphate every day for 90 days. At the end of the 90-day period each participant is evaluated for improvements in strength.
Control Group:

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.

Which coal field location is related to coal fields in the eastern united states and supports the theory of continental drift? eastern india southern africa western australia northern south america