Practice Science TEAS Test

Correct Answer: C

Rationale: The correct answer is C: Iron (II). In heme, the central cation is Iron (II) because it forms a coordination complex with the porphyrin ring. Iron (II) has a +2 charge, allowing it to bind to the nitrogen atoms in the porphyrin ring. This binding is crucial for the proper functioning of heme in carrying oxygen in hemoglobin. Choice A (Cr III) is incorrect because chromium (III) does not typically bind to porphyrin rings in heme. Choice B (Cu II) is incorrect because copper (II) is not commonly found at the center of heme. Choice D (Iron III) is incorrect because in heme, iron is usually in the +2 oxidation state to efficiently bind and release oxygen. Iron (III) is not as effective in this role.

Correct Answer: C

Rationale: The correct answer is C: Spleen. The spleen filters pathogens from the blood through its white pulp, which contains immune cells that detect and destroy harmful microorganisms. The spleen also removes old or damaged red blood cells. A: Lymph nodes filter lymph, not blood. B: Kidneys filter waste from the blood but not pathogens. D: Pancreas is primarily involved in digestion and hormone regulation, not blood filtration.

Correct Answer: B

Rationale: The correct answer is B: To contract and expand the lungs. The diaphragm is a dome-shaped muscle that plays a crucial role in respiration by contracting and relaxing to create changes in lung volume, allowing air to flow in and out of the lungs. When the diaphragm contracts, it flattens, increasing the space in the chest cavity and causing inhalation. When it relaxes, it returns to its dome shape, decreasing the space in the chest cavity and causing exhalation. Incorrect choices: A: To regulate air pressure in the lungs - While the diaphragm indirectly affects air pressure by creating changes in lung volume, its primary role is in creating the necessary space for inhalation and exhalation. C: To store oxygen - The diaphragm is a muscle and does not store oxygen. Oxygen is primarily stored in the blood and tissues. D: To break down carbon dioxide - The diaphragm is not involved in breaking down carbon dioxide. Carbon dioxide is

Correct Answer: A

Rationale: Estrogen is the correct answer because it is the hormone released by the ovaries to mature an egg. Estrogen plays a crucial role in the development of the ovarian follicle, promoting the growth and maturation of the egg. Luteinizing Hormone and Progesterone are also involved in the menstrual cycle but do not directly mature the egg. Testosterone is primarily produced in the testes and plays a role in male reproductive functions, not in egg maturation.

Correct Answer: D

Rationale: The correct answer is D: Hair follicle. The hair follicle is the structure responsible for producing hair. It is located in the dermis and is composed of cells that generate hair growth. The other choices, A: Sudoriferous gland, B: Sebaceous gland, and C: Melanocyte, do not produce hair. Sudoriferous glands produce sweat, sebaceous glands produce oil, and melanocytes produce melanin for skin pigmentation. Therefore, the correct answer is D as it directly relates to hair production.