ATI TEAS Practice Science Test

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.

Correct Answer: C

Rationale: The independent variable is the factor that is intentionally changed by the researcher. In this study, the type of road salt used is the independent variable because it is what the researcher is manipulating to observe its effect on the deicing time. The researcher can control and vary the type of road salt to measure its impact on the deicing process. The other choices are not the independent variable because: A (Deicing time period) is the dependent variable, B (Road used for deicing) is not something that the researcher is intentionally changing, and D (Amount of road salt used) is a controlled variable that can be adjusted but not the main factor being manipulated.

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: The correct answer is C: Flexor. Flexor muscles are responsible for bending a joint by decreasing the angle between the bones they act upon. They contract to bring two body parts closer together. Cardiac muscles (A) are found in the heart and control its pumping action. Extension (B) refers to the straightening of a joint, not bending. Smooth muscles (D) are found in various organs and are not directly involved in joint movement. Therefore, the flexor muscle (C) is the correct choice for causing a joint to bend.

Correct Answer: C

Rationale: The correct answer is C: Paracrine. This is because somatostatin is a chemical signal that acts locally on neighboring cells within the pancreas to inhibit insulin secretion. Paracrine signals are released by one cell and act on nearby cells of the same tissue. Autocrine signals act on the same cell that produced them, which is not the case here. Neuromodulators modulate the activity of neurons, not endocrine cells like in this scenario. Pheromones are chemical signals that are used for communication between individuals of the same species, not within the same organism like in this case.