ati teas 7 science

Correct Answer: C

Rationale: Renin is the correct answer. Renin is an enzyme released by the kidneys in response to low blood pressure. It plays a key role in regulating blood pressure by initiating a series of reactions that ultimately lead to the constriction of blood vessels and retention of water and sodium. This helps to raise blood pressure back to normal levels. Insulin (choice A) is involved in regulating blood sugar levels, not blood pressure. Testosterone (choice B) and Estrogen (choice D) are sex hormones that do not have a direct impact on kidney function and blood pressure regulation.

Correct Answer: C

Rationale: Renin is the correct answer. Renin is an enzyme released by the kidneys in response to low blood pressure. It plays a key role in regulating blood pressure by initiating a series of reactions that ultimately lead to the constriction of blood vessels and retention of water and sodium. This helps to raise blood pressure back to normal levels. Insulin (choice A) is involved in regulating blood sugar levels, not blood pressure. Testosterone (choice B) and Estrogen (choice D) are sex hormones that do not have a direct impact on kidney function and blood pressure regulation.

Correct Answer: D

Rationale: Step 1: Given the object is moving in a circle at a constant speed, it experiences centripetal acceleration towards the center. Step 2: According to Newton's first law, an object in motion stays in motion unless acted upon by a net force. Step 3: The only force causing the object to change its direction is the centripetal force. Step 4: Therefore, the net force acting on the object is required to continuously change its direction. Summary: Choice A is incorrect because the net force is not always present. Choice B is incorrect as centripetal force acts on the object. Choice C is incorrect as speed can be constant in circular motion.

Correct Answer: B

Rationale: The correct answer is B: Humoral immunity. B-cells produce antibodies that circulate in bodily fluids to combat pathogens. This is a key aspect of humoral immunity. A: Cell-mediated immunity involves T-cells directly attacking infected cells, not antibody secretion by B-cells. C: Innate immunity is non-specific and does not involve B-cells producing antibodies. D: Phagocytic immunity involves phagocytes engulfing and destroying pathogens, not antibody secretion by B-cells.

Correct Answer: C

Rationale: The correct answer is C, the Combined oral contraceptive pill. This method uses hormones like estrogen and progestin to prevent ovulation. Firstly, estrogen suppresses follicle-stimulating hormone (FSH) production, inhibiting follicular development. Secondly, progestin thickens cervical mucus, preventing sperm penetration. Lastly, progestin also inhibits luteinizing hormone (LH) surge, preventing ovulation. Spermicide (A) works by killing sperm but does not prevent ovulation. Barrier methods (B) like condoms and diaphragms physically block sperm from reaching the egg but do not affect ovulation. Intrauterine devices (IUDs) (D) work by preventing sperm from fertilizing the egg or by altering the uterine lining, but they do not directly prevent ovulation.