ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
Which of the following statements is correct regarding the pH scale?
Correct Answer: D
Rationale: The correct answer is D. The pH scale measures the acidity or basicity of a substance on a scale of 0 to 14. Each whole pH value below 7 is ten times more acidic than the next higher value. Therefore, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. The difference in pH values indicates the concentration of hydrogen ions in the substance, with lower pH values representing higher acidity and higher pH values representing higher basicity.
Extract:
Question 2 of 5
Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?
Correct Answer: D
Rationale: Carbonic acid is a pivotal buffer in blood that plays a key role in maintaining pH balance. When blood pH rises, indicating increased alkalinity, carbonic acid releases hydrogen ions (H+) to counterbalance the excess base, thereby preventing significant changes in pH levels. This mechanism highlights the essential function of carbonic acid in regulating the acid-base equilibrium in the blood.
Question 3 of 5
Which of the following synthesizes antidiuretic hormone?
Correct Answer: C
Rationale: The correct answer is C: Hypothalamus. The hypothalamus, located in the brain, synthesizes antidiuretic hormone (ADH), also known as vasopressin. ADH is crucial in regulating water balance by controlling the reabsorption of water in the kidneys. This action reduces urine production, helping to maintain proper fluid levels in the body and prevent dehydration. While the pancreas, thymus, and pineal gland play important roles in the endocrine system, they are not responsible for synthesizing antidiuretic hormone.
Question 4 of 5
Which of the following ions binds to the troponin complex, initiating muscle contraction?
Correct Answer: D
Rationale: The correct answer is calcium (D). Calcium ions bind to the troponin complex, initiating muscle contraction. When calcium binds to troponin, it causes a conformational change in the troponin-tropomyosin complex, exposing the binding sites on actin for myosin. This interaction allows muscle contraction by facilitating the sliding of actin and myosin filaments past each other, leading to muscle contraction.
Extract:
Question 5 of 5
The triple point of a substance is the temperature and pressure at which the substance exists as which of the following?
Correct Answer: C
Rationale: The triple point is a specific condition where a substance can exist simultaneously in all three phases: solid, liquid, and gas. The other options do not accurately describe this state.