Science TEAS Practice Test

Correct Answer: C

Rationale: The correct answer is C: Alveoli. Alveoli are tiny sacs in the lungs where gas exchange occurs. Oxygen enters the bloodstream from the alveoli, while carbon dioxide exits the bloodstream to be exhaled. Kidneys (A) filter blood and regulate fluid balance, not involved in gas exchange. Medulla oblongata (B) controls vital functions like breathing and heart rate, but not where gas exchange occurs. Bronchioles (D) are air passages in the lungs, but gas exchange specifically occurs in the alveoli.

Correct Answer: B

Rationale: The correct answer is B: A model. A model is a representation of a natural pattern or occurrence that simplifies complex systems to make them easier to understand and study. Models can simulate natural phenomena that are difficult or impossible to experience directly, allowing scientists to make predictions and test hypotheses. The other choices are incorrect because: A: A theory is an explanation based on evidence and reasoning, not necessarily something difficult to experience directly. C: A law describes a recurring phenomenon but may not involve a representation or simulation of the phenomenon. D: An observation is a direct act of seeing or noting something, not a representation of a complex natural pattern.

Correct Answer: C

Rationale: The correct answer is C: Esophagus. The esophagus is not part of the respiratory system as it is involved in the digestive system, not in the process of breathing. The trachea, bronchi, and larynx are all essential components of the respiratory system responsible for the passage of air into and out of the lungs. The trachea connects the larynx to the bronchi, which further divide into smaller airways to reach the lungs. The larynx contains the vocal cords and plays a role in speech production. In summary, the esophagus is the only choice that is not directly involved in the respiratory system's functions.

Correct Answer: D

Rationale: The correct answer is D because the immune system is responsible for protecting the body from infections by identifying and eliminating harmful pathogens. It helps the body recognize and respond to foreign invaders such as bacteria and viruses. The hypothalamus (Choice A) is not directly involved in immune system function. While the immune system can help remove toxins, its primary role is to combat infections, not filter toxins from the blood (Choice B). Although infections can sometimes trigger the production of more white blood cells, the immune system's primary function is not to stimulate blood cell production (Choice C).

Correct Answer: D

Rationale: The correct answer is D: Homeostasis. The endocrine system is responsible for regulating various physiological processes to maintain internal balance, or homeostasis, within the body. Hormones released by endocrine glands help control metabolism, growth, reproduction, and other functions. Choice A (Heartbeat) is controlled by the cardiovascular system, not the endocrine system. Choice B (Respiration) is controlled by the respiratory system. Choice C (Electrolyte and water balance) is regulated by the kidneys and not directly by the endocrine system. Thus, the primary function of the endocrine system is to maintain homeostasis through hormone regulation.