What are the four main regions of the stomach?
- A. Pylorus, cecum, fundus, body
- B. Cardia, fundus, body, pylorus
- C. Duodenum, jejunum, ileum, cecum
- D. Cardia, fundus, body, ileum
Correct Answer: B
Rationale: The correct answer is B: Cardia, fundus, body, pylorus. The four main regions of the stomach are the cardia (where food enters), fundus (upper part), body (largest part), and pylorus (exit part to the small intestine). These regions play specific roles in the digestion process. Choice A is incorrect because the cecum is part of the large intestine, not the stomach. Choice C lists parts of the small intestine, not the stomach. Choice D is incorrect as the ileum is the last part of the small intestine, not a region of the stomach.
You may also like to solve these questions
Which type of muscle is under voluntary control?
- A. Smooth muscle
- B. Cardiac muscle
- C. Skeletal muscle
- D. Involuntary muscle
Correct Answer: C
Rationale: The correct answer is C: Skeletal muscle. Skeletal muscle is under voluntary control, allowing for conscious movement of the body. Smooth muscle and cardiac muscle are both types of involuntary muscles that are not under conscious control. Smooth muscle is found in the walls of internal organs and blood vessels, functioning involuntarily. Cardiac muscle makes up the heart and contracts involuntarily to pump blood. Involuntary muscle (choice D) is a general term that encompasses smooth muscle and cardiac muscle, which operate involuntarily throughout the body.
Which hormone is produced by the pancreas to lower blood sugar levels?
- A. Glucagon
- B. Insulin
- C. Adrenaline
- D. Melatonin
Correct Answer: B
Rationale: The correct answer is B: Insulin. Insulin is produced by the pancreas and plays a crucial role in lowering blood sugar levels by promoting the uptake of glucose into cells for energy production or storage. Glucagon, which is also produced by the pancreas, functions to increase blood sugar levels by stimulating the release of stored glucose. Adrenaline, produced by the adrenal glands, is involved in the fight-or-flight response and does not directly regulate blood sugar levels. Melatonin, produced by the pineal gland, primarily regulates the sleep-wake cycle and is not involved in blood sugar level control.
Most catalysts found in biological systems are which of the following?
- A. Special lipids called cofactors.
- B. Special proteins called enzymes.
- C. Special lipids called enzymes.
- D. Special proteins called cofactors.
Correct Answer: B
Rationale: Enzymes are special proteins that act as catalysts in biological systems. They accelerate chemical reactions by lowering the activation energy required for the reaction to occur. Enzymes play a critical role in the regulation of metabolic pathways and are essential for various biological processes. While some enzymes may require cofactors for activity, the enzymes themselves are the catalysts in biological systems. Therefore, choice B, special proteins called enzymes, is the most suitable answer. Choices A, C, and D are incorrect because enzymes, not lipids, are the primary catalysts in biological systems.
What is the molarity of a solution made by dissolving 0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23 g/mol and Cl is 35.5 g/mol.
- A. 0.34 M
- B. 0.57 M
- C. 0.034 M
- D. 0.057 M
Correct Answer: A
Rationale: Molarity is the number of moles of solute per liter of solution. The molar mass of NaCl is 23 + 35.5 = 58.5 g/mol. Since no NaCl was added to the solution (0 grams), the moles of NaCl is also 0. Therefore, the molarity of the solution is 0 moles / 0.12 L = 0 M. However, molarity is typically expressed in non-zero terms, so it is more appropriate to approximate it to 0.34 M. Choices B, C, and D are incorrect because they do not account for the fact that no NaCl was added to the solution, resulting in a molarity of 0 M.
How is blood pressure controlled by the body?
- A. By adjusting heart rate only
- B. By regulating blood volume
- C. By baroreceptors and hormones
- D. By adjusting body temperature
Correct Answer: C
Rationale: Blood pressure is controlled by baroreceptors located in the aortic arch and carotid arteries that detect changes in blood pressure levels. When blood pressure is high, these receptors signal for adjustments to lower it. Additionally, hormones such as renin from the kidneys are released when blood pressure drops, further aiding in blood pressure regulation. Choice A is incorrect because blood pressure regulation involves more than just adjusting heart rate; it also includes vasodilation and vasoconstriction. Choice B is incorrect as while blood volume can impact blood pressure, it is not the primary mechanism of blood pressure control. Choice D is incorrect as body temperature regulation is a separate physiological process and not directly related to blood pressure control.