ATI TEAS 7 Science

Correct Answer: B

Rationale: The correct answer is B: Pivot joint. Pivot joints allow rotational movement around a single axis, such as the rotation of the radius around the ulna in the forearm. This type of joint is designed to facilitate the turning or twisting motion. Ball-and-socket joints (A) allow for multi-axial movement, hinge joints (C) enable movement in one direction like a door hinge, and saddle joints (D) have two saddle-shaped surfaces that allow for movement in multiple directions, but not specifically rotational movement around a single axis.

Correct Answer: C

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: A

Rationale: The P wave on an ECG represents atrial depolarization. During the cardiac cycle, the electrical impulse originates in the sinoatrial (SA) node, causing the atria to contract. This depolarization of the atria is reflected as the P wave on the ECG. This occurs before the ventricles depolarize (choice B), repolarize (choice D), or before the atria repolarize (choice C). Therefore, the correct answer is A because the P wave specifically represents atrial depolarization in the cardiac cycle.

Correct Answer: B

Rationale: The correct answer is B: Skeletal. Skeletal muscles are responsible for voluntary movements because they are attached to bones and are under conscious control. They enable us to move our body parts intentionally. Smooth muscles (A) are involuntary and found in internal organs. Cardiac muscles (C) are also involuntary and specific to the heart. Option D simply defines a term and is not a type of muscle.

Correct Answer: B

Rationale: The correct answer is B: 23. In humans, each normal cell contains 23 pairs of chromosomes, making a total of 46 chromosomes. The pairs consist of one chromosome from each parent, ensuring genetic diversity. Choices A, C, and D are incorrect because they do not reflect the accurate number of chromosome pairs in a human cell. Option A (46) is the total number of chromosomes, not pairs. Option C (64) and D (32) are not the correct numbers of chromosome pairs in a human cell.