"Time is the independent variable, and the number of birds is the dependent variable" is the one among the following choices given in the question that states the independent and dependent variables in Sam’s investigation correctly. The correct option among all the options that are given in the question is the second option.
By placing the pots with detergent in the sun and the pots
without detergent in the shade, the student is not comparing the effects that
detergent has in the growing rate of the seeds under the same conditions;
besides, he does not have a control group. Therefore, he will not be able to
determine if the growing rate of the plants were affected by the detergent, the
lack of sunlight, or a combination of both factors.
Answer: This is What drives ocean currents
- Surface is primarily driven by wind (friction from wind transfers energy and momentum to surface water)
- Deep is slower, driven primarily by density (salinity and temperature) differences
- Thermocline: dramatic temp drop 50 m from surface bc sun can't shine
- Halocline: dramatic gradient in saline, increase as it deepens
- Pycnocline: resulting change in density (50-1000)