Question

MEDAL A researcher is interested in finding out if the amount of amylase, a digestive enzyme found in saliva responsible for digesting starch, varies from person to person. Which of the following would be the best way to test this?

Answer 1

Take consistent amounts of saliva samples from a number of people whose meal times vary and measure the quantity of amylase in each sample.

Take varying amounts of saliva samples from a number of people who have not eaten in 8 hours and measure the quantity of amylase in each sample.

Take consistent amounts of saliva samples from a number of people who have not eaten in 8 hours and measure the quantity of amylase in each sample.

Take varying amounts of saliva samples from a number of people whose meal times vary and measure the quantity of amylase in each sample.

Answer 2

@lsherron

Answer 3

I think the best way to approach this would be through a process of elimination.

Amylase is found in saliva - and not in the stomach. (The stomach produces other substances such as intrinsic factor and pepsin). Therefore, we can eliminate three and four right off the bat - there would be very little amylase (if any at all) in the stomach.

Between one and two - you're looking, in an experiment, to have 'standardized' results. Thus, if you have half eating crackers and half eating cheese, that's another variable you've just introduced into your experiment - this complicates your results unnecessarily. The best choice is the second one, because by ensuring that they all haven't eaten in 8 hours, you're ensuring your results will be consistent.