ATI TEAS Practice Science Test

Correct Answer: D

Rationale: The correct answer is D: Melanocyte-stimulating hormone. Melanocyte-stimulating hormone stimulates the melanocytes in the skin to produce melanin, the pigment responsible for skin color. This hormone darkens the skin by increasing melanin production. A: Follicle-stimulating hormone is involved in reproductive functions, not skin color changes. B: Growth-stimulating hormone primarily affects growth and development, not skin color. C: Thyroid-stimulating hormone regulates thyroid function, not skin color.

Correct Answer: D

Rationale: The correct answer is D: Sucrase. Sucrose is a disaccharide composed of glucose and fructose. Sucrase is the enzyme responsible for breaking down sucrose into its constituent sugars, glucose, and fructose. Lactase (A) breaks down lactose, Maltase (B) breaks down maltose, and Peptidase (C) breaks down proteins. In this case, since we are dealing with sucrose from the birthday cake, the enzyme needed is sucrase to catalyze the breakdown of sucrose into its simpler sugars.

Correct Answer: B

Rationale: The correct answer is B: Prone. Prone position allows access to the stomach as the patient lies on their stomach, facilitating examination or procedures on the abdominal area. In the prone position, the stomach is easily accessible for palpation or diagnostic tests. The other choices are incorrect because: A: Medial refers to the midline of the body and does not specifically provide access to the stomach. C: Superficial refers to the location near the surface and does not relate to positioning for stomach access. D: Supine refers to lying on the back, which is not ideal for direct access to the stomach.

Correct Answer: B

Rationale: The correct answer is B: Cytoplasm. Pyruvate is an intermediate product of glycolysis, which occurs in the cytoplasm of the cell. The biochemist isolating pyruvate is working with the cytoplasm because that's where glycolysis takes place. Chloroplasts (A) are involved in photosynthesis, not glycolysis. Mitochondria (C) are responsible for aerobic respiration, where pyruvate is eventually transported to. The nucleus (D) contains the cell's genetic material and is not directly involved in pyruvate metabolism. Thus, the biochemist is likely isolating pyruvate from the cytoplasm.

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.