ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C: Nephron. The nephron is the functional unit of the kidney responsible for filtering blood and reabsorbing essential substances like water, salts, and nutrients back into the body. It consists of various components like the glomerulus, proximal tubule, loop of Henle, and distal tubule, each playing a specific role in the reabsorption process. The renal artery brings blood to the kidney for filtration by the nephron, while the renal vein carries filtered blood away from the kidney. The glomerulus is a part of the nephron responsible for initial filtration of blood. Thus, the nephron is the correct structure for reabsorption, making choices A, B, and D incorrect.

Correct Answer: C

Rationale: The correct answer is C: Buffering system. The body maintains a relatively constant blood pH level through the buffering system, which involves the action of bicarbonate ions, carbonic acid, and other buffering molecules that help regulate pH by neutralizing excess acids or bases. This system acts quickly to prevent drastic changes in blood pH when there are fluctuations in blood carbon dioxide concentration. Cellular respiration (A) generates carbon dioxide, gas exchange (B) involves the exchange of gases in the lungs, and deoxygenation (D) refers to the loss of oxygen by the blood, but these processes are not primarily responsible for maintaining blood pH stability.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen bonding. Water molecules exhibit hydrogen bonding, where the partially positive hydrogen of one water molecule is attracted to the partially negative oxygen of another water molecule. This strong intermolecular force leads to the cohesive forces that create high surface tension in water. B: London dispersion forces are weaker and do not contribute significantly to water's high surface tension. C: Ionic bonding involves the transfer of electrons between atoms, not relevant to water's surface tension. D: Metallic bonding occurs in metals and is not related to the surface tension of water.

Correct Answer: B

Rationale: The correct answer is B: Protons and neutrons only. Electrons are not found in the nucleus, as they orbit around the nucleus in electron shells. Protons and neutrons are the subatomic particles found within the nucleus of an atom. Protons have a positive charge, while neutrons are neutral. The nucleus contains almost all of the atom's mass and is positively charged due to the presence of protons. Choice A is incorrect because electrons are not part of the nucleus. Choice C is incorrect because electrons are not present in the nucleus. Choice D is incorrect as protons and neutrons are indeed constituents of the atomic nucleus.

Correct Answer: B

Rationale: The correct answer is B: Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This is a crucial step in the pulmonary circulation system. The pulmonary vein carries oxygenated blood from the lungs back to the heart, so it does not transport blood from the heart to the lungs. The aorta is responsible for carrying oxygenated blood from the heart to the rest of the body, not to the lungs. The superior vena cava is a large vein that carries deoxygenated blood from the upper body to the heart, not to the lungs. Therefore, the pulmonary artery is the correct choice for transporting blood from the heart to the lungs.