ati teas 7 science

Correct Answer: C

Rationale: The correct answer is C because the main function of the pancreas is to produce enzymes that help digest food. These enzymes are released into the small intestine to break down carbohydrates, proteins, and fats. Choice A is incorrect as the pancreas does not store or break down food. Choice B is incorrect as nutrient absorption primarily occurs in the small intestine, not the pancreas. Choice D is incorrect as regulating blood sugar levels is primarily the role of the endocrine portion of the pancreas, not its main function.

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: A

Rationale: The correct answer is A: Pulmonary vein. The pulmonary vein is the only blood vessel among the choices that carries oxygenated blood from the lungs back to the heart. The pulmonary artery (B) carries deoxygenated blood from the heart to the lungs. The aorta (C) carries oxygenated blood from the heart to the rest of the body. The vena cava (D) carries deoxygenated blood from the body back to the heart. Therefore, the pulmonary vein is the only blood vessel in the list that fits the description of carrying oxygenated blood from the lungs to the heart.

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: C

Rationale: The correct answer is C: Testosterone. Testosterone is crucial for stimulating sperm production in males as it is the primary male sex hormone responsible for regulating the development of male reproductive tissues. It plays a key role in the production of sperm cells in the testes. Estrogen (A) and Progesterone (B) are female sex hormones and do not have a direct role in sperm production. Insulin (D) is a hormone that regulates blood sugar levels and is not involved in the process of sperm production.