TEAS Practice Test Science

Correct Answer: C

Rationale: The correct answer is C: Mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for producing ATP through cellular respiration. This process involves the breakdown of glucose to generate energy in the form of ATP. Ribosomes (A) are responsible for protein synthesis, the nucleus (B) houses the cell's genetic material, and the endoplasmic reticulum (D) is involved in protein synthesis and lipid metabolism, but not ATP production. Mitochondria's unique structure and enzymes make them the primary site for ATP production in the cell.

Correct Answer: C

Rationale: The correct answer is C: Thymus. The thymus is responsible for maturing T cells, a type of white blood cell crucial for immune responses. The thymus is where immature T cells develop into functional T cells through a process called thymic education. The other choices are incorrect because the hypothalamus (A) is involved in regulating hormones, the pineal gland (B) regulates sleep-wake cycles, and the thyroid (D) produces hormones that regulate metabolism. These structures do not have a direct role in maturing T cells.

Correct Answer: B

Rationale: The pancreas produces insulin to lower blood sugar levels and glucagon to raise them. Insulin helps cells take in glucose for energy or storage. Glucagon signals the liver to release stored glucose. Storing glucose (option C) is not the primary function of the pancreas. Adrenaline (option D) is produced by the adrenal glands, not the pancreas.

Correct Answer: D

Rationale: The correct answer is D: Ventilation. Ventilation specifically refers to the mechanical act of breathing, which involves the movement of air in and out of the lungs. This process is essential for the exchange of oxygen and carbon dioxide in the body. A: Diffusion is the process of molecules moving from an area of high concentration to an area of low concentration. While diffusion plays a role in gas exchange during respiration, it is not the mechanical act of breathing itself. B: Perfusion refers to the process of blood flow through the tissues. Although perfusion is vital for delivering oxygen to the body's cells, it is not the mechanical act of breathing. C: Respiration encompasses the entire process of gas exchange in the body, including both ventilation and the exchange of gases at the cellular level. While respiration is closely related to breathing, it is not specifically the mechanical act of breathing.

Correct Answer: D

Rationale: The correct answer is D: Takes shape of container. Liquids do not have a fixed shape but take the shape of the container they are in due to the particles being able to flow and move past each other. Choice A is incorrect as liquids have moderate atomic attraction, not high. Choice B is incorrect as liquids have a fixed volume but not a fixed shape. Choice C is incorrect as liquids can have varying pressures depending on the conditions.