Dental Admissions Test (DAT) Practice Test

What is true of the digestive, respiratory, and urinary systems?

1. a. They function independently

2. b. They have no impact on substances in the blood

3. c. They maintain balance of substances in the blood

4. d. They produce blood cells

The correct answer is: c. They maintain balance of substances in the blood

The digestive, respiratory, and urinary systems do not function independently, as they work together to maintain homeostasis in the body. While the respiratory system exchanges gases and the digestive system processes and absorbs nutrients, the urinary system helps to regulate and eliminate waste products from the body. Additionally, these systems all have a direct impact on maintaining the balance of substances in the blood, such as oxygen, nutrients, and waste products. Option A is incorrect because they do not function independently. Option B is incorrect because they do have an impact on substances in the blood. Option D is incorrect because the production of blood cells primarily occurs in the bone marrow.