ATI TEAS Practice Science Test

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver plays a crucial role in storing and metabolizing vitamins, releasing them as needed when intake decreases. It helps maintain vitamin levels in the body. The other choices are incorrect because the appendix has no role in vitamin absorption or regulation, the pancreas primarily aids in digestion and hormone regulation, and the stomach's main function is to break down food, not regulate vitamin levels.

Correct Answer: C

Rationale: To calculate the mass of the atom, we add the number of protons and neutrons since electrons have negligible mass. In this case, 17 protons + 20 neutrons = 37. Therefore, the correct answer is C. Choice A is incorrect because it only considers the number of protons. Choice B is incorrect because it only considers the number of neutrons. Choice D is incorrect because it does not take into account the total number of protons and neutrons in the atom.

Correct Answer: A

Rationale: The correct answer is A: They are small and soluble. Small molecules can easily diffuse across cell membranes, while soluble molecules can dissolve in the cell's aqueous environment. This combination allows the signals to pass through the membrane and bind to intracellular receptors. Choice B (large and soluble) is incorrect because large molecules have difficulty crossing the membrane. Choices C (small and insoluble) and D (large and insoluble) are incorrect as they do not facilitate the passage of signals across the cell membrane for binding to intracellular receptors.

Correct Answer: B

Rationale: The correct answer is B: Ribcage. The ribcage is a bony structure that surrounds and protects the lungs. It consists of ribs, sternum, and thoracic vertebrae, forming a protective cage around the vital organs in the thoracic cavity. The ribs provide a barrier against external forces and help maintain the shape and integrity of the lungs. The other choices are incorrect because the femur is a bone in the leg, the scapula is a bone in the shoulder, and the skull protects the brain, not the lungs.

Correct Answer: B

Rationale: The correct answer is B because urine is formed in the kidney during the process of fluid filling the collecting duct. This is where the final concentration and composition of urine are regulated. Before reaching the collecting duct, the initial filtration of blood occurs in the glomerulus (eliminating options C) and the fluid does not become urine until it has passed through the collecting duct (eliminating options A and D). So, the correct sequence is filtration in the glomerulus, reabsorption and secretion in the tubules, and final urine formation in the collecting duct.