TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: To exchange gases. The main function of the respiratory system is to facilitate the exchange of oxygen and carbon dioxide between the body and the external environment. This process occurs in the lungs through breathing, where oxygen is taken in and carbon dioxide is expelled. Absorbing nutrients (A) is the function of the digestive system, transporting oxygen (C) is part of the circulatory system's role, and regulating blood pressure (D) is primarily controlled by the cardiovascular system.

Correct Answer: B

Rationale: The correct answer is B: Artery. Arteries are responsible for carrying oxygenated blood from the heart to the body. Arteries have thick walls and are designed to withstand the high pressure generated by the pumping action of the heart. Oxygenated blood is pumped out of the heart through the aorta, the largest artery in the body, and then distributed to various parts of the body through smaller arteries. A: Veins carry deoxygenated blood back to the heart. C: Capillaries are tiny blood vessels where the exchange of oxygen and nutrients occurs. D: Lymphatic vessels are responsible for transporting lymph, not oxygenated blood. In summary, arteries are specifically designed to carry oxygenated blood away from the heart, making them the correct choice in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Helicase. Helicase is responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This allows the DNA strands to separate and serve as templates for the synthesis of new DNA strands by DNA polymerase. Ligase is responsible for joining the DNA fragments together, nuclease is involved in DNA repair by cutting out damaged DNA, and polymerase is responsible for synthesizing new DNA strands based on the template strands. Therefore, only helicase directly unwinds the double-stranded DNA during replication.

Correct Answer: B

Rationale: The correct answer is B: Cerebellum. The cerebellum is responsible for coordinating muscle movements by receiving information from the sensory systems, spinal cord, and other parts of the brain to regulate motor movements. It plays a crucial role in maintaining balance, posture, and smooth coordination of voluntary movements. The other choices are incorrect because: A: The cerebrum is primarily involved in higher brain functions such as thinking, decision-making, and emotions. C: The thalamus acts as a relay station for sensory information but does not directly control muscle coordination. D: The medulla oblongata is responsible for regulating vital functions such as breathing, heart rate, and blood pressure, but not specifically muscle coordination.

Correct Answer: D

Rationale: The correct answer is D, the cerebrum. The cerebrum is the largest part of the brain and is responsible for higher brain functions such as thought, reasoning, memory, and voluntary actions. It consists of the cerebral cortex, which plays a crucial role in processing sensory information and controlling motor functions. The amygdala (A) is involved in emotions and memory, the brain stem (B) controls basic life functions like breathing and heart rate, and the cerebellum (C) coordinates movement and balance. Therefore, the cerebrum is the correct choice for higher brain functions.