ati teas 7 science

Correct Answer: D

Rationale: The main function of the lungs is to exchange oxygen and carbon dioxide between the body and the environment. This process, known as respiration, is essential for cellular function. Step 1: Oxygen is inhaled into the lungs and diffuses into the bloodstream. Step 2: Carbon dioxide produced by cells is carried to the lungs via the bloodstream and exhaled. Choice A is incorrect as the primary function of the lungs is gas exchange, not nutrient transport. Choice B is incorrect as movement coordination is a function of the nervous system. Choice C is incorrect as waste filtration is primarily done by the kidneys and liver.

Correct Answer: C

Rationale: The correct answer is C: GABA. GABA is an inhibitory neurotransmitter that slows down neuron activity by binding to GABA receptors, leading to hyperpolarization of the neuron and reducing the likelihood of firing an action potential. This process helps to prevent overexcitation in the nervous system. A: Acetylcholine is primarily an excitatory neurotransmitter involved in muscle control and cognitive function. B: Dopamine plays a role in reward-motivated behavior and movement, but it is not primarily responsible for slowing down neuron activity. D: Serotonin is involved in regulating mood, appetite, and sleep, but it does not directly slow down neuron activity to prevent overexcitation.

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: C

Rationale: Renin is the correct answer. Renin is an enzyme released by the kidneys in response to low blood pressure. It plays a key role in regulating blood pressure by initiating a series of reactions that ultimately lead to the constriction of blood vessels and retention of water and sodium. This helps to raise blood pressure back to normal levels. Insulin (choice A) is involved in regulating blood sugar levels, not blood pressure. Testosterone (choice B) and Estrogen (choice D) are sex hormones that do not have a direct impact on kidney function and blood pressure regulation.

Correct Answer: B

Rationale: The correct answer is B because not all fungi are parasitic and harmful to humans. Some fungi are beneficial, while others are neutral. A is correct as fungi can be unicellular or multicellular. C is true as fungi are crucial in breaking down organic matter. D is accurate as some fungi, such as mushrooms, are consumed as food. Overall, choice B is false because it wrongly generalizes all fungi as harmful, which is not the case.