ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C (2+ or 3+). Iron is a transition metal, meaning it has variable oxidation states. Iron commonly forms cations with charges of 2+ (Fe²⁺) or 3+ (Fe³⁺) due to its ability to lose 2 or 3 electrons, respectively, from its outer shell. This is consistent with the typical behavior of transition metals to exhibit multiple oxidation states. Choices A and B are incorrect because iron does not commonly form cations with charges of 2- or 3-. Choice D is incorrect as iron typically forms cations with a positive charge, not a negative charge.

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: C

Rationale: The correct answer is C: Nasal passages. Nasal passages contain mucous membranes that produce mucus to humidify and warm inhaled air. The mucus traps particles and adds moisture to the air, making it easier for the lungs to absorb oxygen. The trachea (A) is a passageway for air but does not actively humidify or warm it. The larynx (B) is responsible for sound production and protecting the airway, not for conditioning air. The bronchi (D) are branching airways that lead from the trachea to the lungs, but they do not play a direct role in humidifying or warming inhaled air.

Correct Answer: C

Rationale: The correct answer is C: Luteinizing hormone (LH). LH surge triggers ovulation by causing the mature ovarian follicle to release the egg. Estrogen and progesterone play important roles in regulating the menstrual cycle but are not the primary triggers for ovulation. FSH stimulates the growth of ovarian follicles but does not directly trigger ovulation.

Correct Answer: A

Rationale: The correct answer is A: Hypothalamus. The hypothalamus plays a vital role in regulating body temperature by responding to internal and external temperature changes. It coordinates the body's response to maintain a stable temperature through processes like sweating or shivering. B: Cerebellum is responsible for coordinating movement and balance, not body temperature regulation. C: Pituitary gland regulates hormone production but not directly involved in body temperature regulation. D: Thyroid gland controls metabolism and energy levels but not primarily responsible for regulating body temperature.