what is glucagon where is it produced and what is its function

ATI TEAS 7

ATI TEAS Science Practice Test

1. What is glucagon, where is it produced, and what is its function?

A. Produced in the liver, releases glucose
B. Produced in the pancreas, raises blood sugar
C. Produced in the pancreas, lowers blood sugar
D. Produced in the adrenal glands, regulates stress response

Correct answer: B

Rationale: Glucagon is a hormone produced in the pancreas and functions to raise blood sugar levels. It does so by signaling the liver to release stored glucose into the bloodstream. Therefore, the correct answer is B, 'Produced in the pancreas, raises blood sugar.' Choices A, C, and D describe functions or locations of other hormones, not glucagon. Glucagon is specifically released by alpha cells in the pancreas, making option B the correct choice.

2. What is the difference between a prokaryotic cell and a eukaryotic cell?

A. Prokaryotic cells have a nucleus, while eukaryotic cells do not
B. Eukaryotic cells have a nucleus, while prokaryotic cells do not.
C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells do not.
D. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Correct answer: B

Rationale: - Prokaryotic cells are simpler and do not have a true nucleus. Their genetic material is located in the nucleoid region, which is not enclosed by a membrane. - Eukaryotic cells are more complex and have a true nucleus that houses the genetic material, enclosed within a nuclear membrane. - Both prokaryotic and eukaryotic cells have organelles, but eukaryotic cells have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, while prokaryotic cells lack these membrane-bound organelles.

3. What does the T wave on an ECG correspond to?

A. Atrial depolarization
B. Ventricular depolarization
C. Atrial repolarization
D. Ventricular repolarization

Correct answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. Following ventricular depolarization, which is represented by the QRS complex, the ventricles undergo repolarization during the T wave. This phase signifies the recovery of ventricular muscle cells as they prepare for the subsequent depolarization cycle. Choices A, B, and C are incorrect because the T wave specifically reflects the repolarization of the ventricles, not the atria or their respective depolarization or repolarization phases.

4. What is the role of the diaphragm in the respiratory system?

A. To regulate blood pressure
B. To contract and expand the lungs
C. To produce red blood cells
D. To absorb oxygen

Correct answer: B

Rationale: The correct answer is B: To contract and expand the lungs. The diaphragm plays a crucial role in the respiratory system by contracting and expanding the lungs. When it contracts, it flattens, increasing the volume of the thoracic cavity and causing air to be drawn into the lungs. Conversely, when it relaxes, it moves back up, decreasing the thoracic cavity volume and pushing air out of the lungs. This process is essential for breathing and the exchange of oxygen and carbon dioxide in the body. Choices A, C, and D are incorrect. The diaphragm is not involved in regulating blood pressure, producing red blood cells, or absorbing oxygen. Its primary function is to aid in respiration by facilitating breathing through its contraction and relaxation movements.

5. In aerobic respiration, how many ATP molecules are produced per molecule of FADH2?

A. 1
B. 2
C. 3
D. 4

Correct answer: B

Rationale: The correct answer is B: 2. During aerobic respiration, each molecule of FADH2 produces 2 ATP molecules. FADH2 enters the electron transport chain and contributes to the generation of ATP. Choice A (1), Choice C (3), and Choice D (4) are incorrect because FADH2 specifically yields 2 ATP molecules per molecule in the process of aerobic respiration.