ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C: Vitamin K. Vitamin K is essential for blood clotting as it helps in the synthesis of clotting factors. Without adequate vitamin K, the blood cannot clot properly, leading to excessive bleeding. Vitamin A (Choice A) is crucial for vision and immune function, not blood clotting. Vitamin C (Choice B) is important for collagen synthesis and immune function, not blood clotting. Vitamin D (Choice D) is essential for bone health and immune function, not blood clotting. Thus, the correct choice is Vitamin K as it plays a direct role in the blood clotting process.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver is responsible for detoxifying chemicals and metabolizing drugs due to its enzymes that break down substances. It also helps in excreting waste products. The kidneys (A) filter blood and regulate fluid balance. The heart (C) pumps blood throughout the body. The pancreas (D) produces digestive enzymes and insulin. Thus, the liver is the primary organ involved in detoxification and drug metabolism.

Correct Answer: B

Rationale: The correct answer is B: Synapse. The synapse is the point of contact between a motor neuron and a muscle fiber where communication occurs via neurotransmitters like acetylcholine to initiate muscle contraction. A: Sarcomere is a structural unit of a muscle fiber, not the point of contact for communication. C: Tendon is a fibrous connective tissue that attaches muscle to bone, not involved in neuron-muscle communication. D: Myofibril is a cylindrical organelle within muscle fibers where muscle contractions occur, but it is not the specific point of contact for neuron communication.

Correct Answer: B

Rationale: When a sound wave travels from air to water, its speed decreases because sound travels faster in denser mediums. Water is denser than air, so the speed of sound decreases. This decrease occurs due to the change in the medium's properties affecting the wave propagation speed. The other choices are incorrect because the speed of sound is not dependent on frequency (choice D) and it doesn't remain the same (choice C) when transitioning between different mediums. Choice A is incorrect as an increase in density leads to a decrease in speed, not an increase.

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.