Question

Scientists have believed for many years that marine temperatures drop as ocean depth increases. What experimental method would best test this hypothesis, and why?

a.Bring samples of ocean water from various depths to the lab and measure the temperature of each sample, because this most directly measures water temperature
b.Send a robot to measure the temperature of the ocean at various depths and plot the data on a graph, because ocean temperature may change with depth
c.Capture fish from various ocean depths and measure the temperature of their tissues, because this directly measures the temperature of living systems
d.Collect rocks from various ocean depths and determine what temperature was present during the rocks' formation, because rocks do not change once they are formed

Answer 1

B. A is invalid because bringing water outside of the ocean would mean a temperature change and would therefore be inaccurate. C is also invalid because of temperature change. D is invalid because the rock may not have formed in the ocean

Answer 2

b. Send a robot to measure the temperature of the ocean at various depths and plot the data on a graph, because ocean temperature may change with depth

Step-by-step explanation:

Remember that in a scientific experiment we are supposed to validate or reject our hypotesis, in this case we must determine if water's termerature of the ocean changes depending of the depth. The hypotesis would be: As ocean depth increases, water temperature drops.

The only way to validate or reject this is to measure the temperature of water at different depths. Option B is the only one that gives us this possibility, technology allows us to send a robot into the ocean and submerge measuring the different temperatures.

The other options take the subject of study out of the controled zone, by extracting water or a fish from the depths and measuring it's tempreature, we take the risk that other factors, such as surface's temperature, affect the result.