The thing that would mostly make the results of the experiment invalid would be the students themselves. No one is built the same, and the exact same food can have very different effects on different people.
A. Hormones act as signal molecules between all body systems
Peripheral Chemoreceptors (Carotid + Aortic Bodies) and Central Chemoreceptors in the Medulla Oblongata detect high Carbon Dioxide levels in the blood during exercise. The respiratory centre in the Medulla Oblongata + PONS stimulate the intercostal muscles and the diphragm to contract in order to increase the rate and depth of breathing as to decrease levels of Carbon dioxide in the blood.
The thyroid gland secretes thyroxine which speeds up metabolism (the rate at which cells use glucose)
Answer:
The correct answer is: upper esophageal sphincter.
Explanation:
The alimentary canal is a very long tract responsible for the digestion of the food. It is composed of several organs with many different and important functions. The alimentary canal also has a few sphincters, which are muscular valves that open and close when needed for the food to pass or be retained.
The first sphincter is the upper esophageal sphincter. One particularity of this sphincter is that is one of the few sphincters in the body that opens and closes under our conscious control, which happens when we decide to swallow our food.
From the first to the last, the order of the sphincters in the gastrointestinal tract is: upper esophageal sphincter, lower esophageal sphincter or gastroesophageal sphincter, pyloric sphincter, ileocecal sphincter, and anus.
I believe it is B. Growing
Hope this helps!
Answer:
B. similar to the cells just treated with the dye - 0% dead
Explanation:
According to this question, an experiment was set up in which kidney cells were treated with a chemical for different amounts of time. Hence, the independent/manipulable variable is the CHEMICAL.
Based on the observation of the group of cells, a cell that has been damaged by the chemical will appear pink when treated with dye while a cell treated with only due but no chemical will not appear pink.
A NEGATIVE CONTROL is the group in an experiment that is not treated with the independent variable i.e. doesn't receive experimental treatment. Since the independent variable in this experiment is the CHEMICAL, the negative control will be the group that doesn't receive the chemical treatment. Hence, the negative control is similar to the cells just treated with the dye - 0% dead
