ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: Ball-and-socket joint. This joint allows for the greatest range of motion due to its structure, where a rounded bone fits into a cup-like socket, enabling movement in multiple directions. This design permits flexion, extension, abduction, adduction, and rotation, providing a wide range of motion compared to other joint types. A: Hinge joints allow movement in one plane (like the elbow or knee). C: Pivot joints allow rotation around a central axis (like the neck). D: Saddle joints have more limited motion (like the thumb).

Correct Answer: A

Rationale: The correct answer is A: Solid. Solids have both a definite volume and a definite shape because the particles are tightly packed and vibrate in fixed positions. This leads to a rigid structure and minimal movement, maintaining the shape and volume. In contrast, liquids (B) have a definite volume but take the shape of their container, gases (C) have neither a definite shape nor volume as they expand to fill the container, and plasmas (D) have no definite shape or volume due to their high energy state.

Correct Answer: B

Rationale: The correct answer is B: Acting as a protective sac surrounding the heart. The pericardium is a double-walled sac that surrounds and protects the heart. It provides physical protection against external forces and prevents overfilling of the heart. Choices A, C, and D are incorrect as they do not accurately describe the function of the pericardium. Choice A refers to the role of heart valves, choice C refers to the role of the heart's electrical system, and choice D refers to the function of the atrioventricular node.

Correct Answer: A

Rationale: The correct answer is A: Neuron. Neurons are the fundamental unit of the nervous system because they are specialized cells that transmit information through electrical and chemical signals. Neurons have a unique structure with dendrites, cell body, and axon, allowing them to receive, process, and transmit signals. Nerves (B) are bundles of neurons, ganglia (C) are clusters of neuron cell bodies, and neuroglia (D) are support cells in the nervous system. Neurons are the primary functional unit responsible for communication in the nervous system.

Correct Answer: D

Rationale: The correct answer is D: Trachea. The trachea is the largest part of the airway. It is a tube that connects the larynx to the bronchi, allowing air to pass into and out of the lungs. The trachea is larger than the bronchi, bronchioles, and alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Bronchi are the main air passages into the lungs, branching off from the trachea. Bronchioles are smaller branches of the bronchi. Therefore, the trachea is the largest structure among the given choices, making it the correct answer.