ATI TEAS 7 Science Practice Test

Correct Answer: C

Rationale: A substance is considered acidic if its pH is less than 7. pH values below 7 indicate acidity, while pH values above 7 indicate alkalinity or basicity. Substances with a pH less than 7 are categorized as acidic, not above it. Therefore, a substance is classified as acidic if its pH is less than 7, making choice C the correct answer. Choices A, B, and D are incorrect because a pH of 12, 9, and 4, respectively, are all above 7, and therefore not indicative of acidity.

Correct Answer: A

Rationale: The corrected question is asking for a blood vessel that carries oxygenated blood back to the heart. The pulmonary vein is the correct choice as it carries oxygenated blood from the lungs back to the heart during systemic circulation. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. The aorta is the main artery that carries oxygenated blood away from the heart to the body. The superior vena cava returns deoxygenated blood from the upper body back to the heart.

Correct Answer: A

Rationale: The correct answer is A: Alveoli. Gas exchange occurs in the alveoli, which are tiny air sacs in the lungs. Oxygen from the air we breathe diffuses into the blood vessels surrounding the alveoli, while carbon dioxide from the blood diffuses into the alveoli to be exhaled. The bronchi, larynx, and pharynx are all part of the respiratory system but are not directly involved in gas exchange. The bronchi are airways that lead to the lungs, the larynx is the voice box, and the pharynx is the throat. These structures are important for breathing and vocalization but do not participate in the exchange of gases between the respiratory system and the circulatory system.

Correct Answer: D

Rationale: Enzymes are large molecules that act as catalysts, accelerating chemical reactions by lowering the activation energy required for the reactions to occur. In the context of biological reactions, enzymes function as catalysts, not suppressors, triggers, or targets. The use of 'large' and 'catalysts' accurately describes the nature and role of enzymes in facilitating biological processes.

Correct Answer: A

Rationale: The correct answer is A: 4. There are 4 types of tissues in the human body: epithelial, connective, muscle, and nervous. Epithelial tissue covers the body surfaces, connective tissue provides support and structure, muscle tissue enables movement, and nervous tissue transmits signals. Choices B, C, and D are incorrect as they do not represent the accurate number of tissue types found in the human body.