ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B: Myosin. Myosin is the protein complex responsible for the thick filament in the sarcomere. It forms cross-bridges with actin during muscle contraction. Actin (choice A) is the thin filament in the sarcomere. Tropomyosin (choice C) is a regulatory protein that covers the myosin-binding sites on actin when the muscle is at rest. Troponin (choice D) is another regulatory protein that helps regulate muscle contraction by binding calcium ions.

Correct Answer: B

Rationale: The correct answer is B: Bronchitis. Bronchitis is the inflammation of the bronchi, leading to symptoms like cough and mucus production. Pneumonia (A) is an infection in the lungs, not specifically inflammation of the bronchi. Emphysema (C) is a chronic lung condition characterized by damaged air sacs in the lungs, not bronchial inflammation. Pleurisy (D) is inflammation of the lining of the lungs, not the bronchi. Therefore, based on the symptoms described, bronchitis is the most suitable term for inflammation of the bronchi.

Correct Answer: B

Rationale: The gravitational potential energy of an object is determined by its position relative to the ground. The higher the object is from the ground, the greater its gravitational potential energy. This is because the gravitational potential energy is directly proportional to the distance from the ground. Therefore, choice B, the distance from the ground, affects the gravitational potential energy of an object the most. Incorrect choices: A: The mass of the object does affect the gravitational potential energy, but it is not the most significant factor. C: The gravitational force affects the weight of an object but does not directly determine its gravitational potential energy. D: The shape of the object does not affect its gravitational potential energy; only the distance from the ground matters.

Correct Answer: D

Rationale: Certainly! The correct answer is D because saltatory conduction is faster than normal nerve conduction (A), occurs from one node of Ranvier to the next (B), and only occurs in myelinated neurons (C). This process involves the rapid transmission of action potentials in myelinated axons, where the impulse "jumps" from one node of Ranvier to the next, skipping the myelinated regions in between. This allows for faster conduction speeds compared to continuous conduction in unmyelinated neurons. Therefore, all of the statements in options A, B, and C are accurate descriptions of saltatory conduction, making option D the correct choice.

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.