Question

Identify a dependent variable in the experimental design. Identify a negative control for the effects of hormone addition. Identify a likely reason why the researchers continued their experiment for 240 minutes.

Answer 1

Hello. This question is incomplete, you forgot to show the necessary experiment for this question to be answered. It is important to remember that you need to post the full question so that we can answer it as you deserve.

The experiment is shown in the figure attached below.

Answer:

The dependent variable is the intracellular signaling pathways in hepatocytes. The negative control would be the activation of different signaling pathways, through the similar regulation of carbohydrate metabolism by hepatocytes when cells are treated with growth hormone or insulin. The scientists continued the experiment for 240 minutes, because the hormones have different signaling times.

Explanation:

Dependent variable is one that is influenced by the independent variable and generates a result. In the case of the experiment shown in the figure below, we can see that scientists wanted to evaluate the influence of growth hormone and insulin, on the activation of intracellular signaling pathways in hepatocytes, the same or different. For this reason, we can see that the dependent variable was the intracellular signaling pathways in hepatocytes.

Negative control is a biological process that promotes a result contrary to the stimulus performed. With that, we can affirm that a negative control in the addition of hormones, would be the  activation of different signaling pathways, through the similar regulation of carbohydrate metabolism by hepatocytes when cells are treated with growth hormone or insulin.

Finally, scientists decided to keep the experiment for 240 minutes, because different homorns, have different action times, so 240 minutes would be the ideal time for the two hormones to have acted and their results could be analyzed.