ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. This is the protective fluid that surrounds the brain and spinal cord. It acts as a cushion, providing mechanical protection, and helps to maintain a stable environment for the central nervous system. Blood (A) does not directly surround the brain and spinal cord. Myelin sheath (C) is a protective covering of nerve fibers, not the fluid surrounding the brain and spinal cord. Insulin (D) is a hormone involved in regulating blood sugar levels and is not the fluid that protects the brain and spinal cord.

Correct Answer: B

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: Autoimmune disease. In autoimmune diseases, the immune system mistakenly targets healthy cells and tissues, causing inflammation and damage. This is due to a breakdown in self-tolerance mechanisms. Immunodeficiency (A) is the opposite, where the immune system is weakened. Allergy (C) is an immune response to harmless substances, not attacking healthy tissues. Cancer (D) involves uncontrolled cell growth, not immune system attacking healthy tissues.

Correct Answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs during respiration. Oxygen from the air we breathe diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (A) is a tube that carries air to and from the lungs, the bronchi (C) are branches of the trachea, and the diaphragm (D) is a muscle that helps with breathing but is not directly involved in gas exchange. Therefore, the alveoli are responsible for gas exchange in the respiratory system.