ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
Which of the following physiological responses is caused by the release of anti-diuretic hormone?
Correct Answer: D
Rationale: The correct answer is D: Increase in water reabsorption in the collecting duct. Anti-diuretic hormone (ADH), also known as vasopressin, acts on the kidneys to increase water reabsorption in the collecting ducts, leading to the concentration of urine and conservation of water in the body. This hormone helps regulate water balance by decreasing urine output and increasing blood volume and pressure when needed.
Extract:
Question 2 of 5
Which substance protects the body from ultraviolet rays?
Correct Answer: D
Rationale: Melanin is the pigment responsible for skin color and serves as a natural defense against ultraviolet (UV) rays. When the skin is exposed to UV rays, melanin production increases to absorb and dissipate the radiation, acting as a protective mechanism. This helps prevent DNA damage, reducing the risk of skin cancer and other UV-induced skin issues. Therefore, melanin is the substance that effectively shields the body from the harmful effects of UV radiation.
Question 3 of 5
Which of the following substances is excreted by the sweat glands in response to the breakdown of proteins and the formation of ammonia?
Correct Answer: C
Rationale: The correct answer is Urea. Sweat glands excrete urea in response to the breakdown of proteins and the formation of ammonia. Urea is a waste product formed in the liver by the breakdown of amino acids. It is then excreted by the kidneys in urine and by sweat glands through perspiration. Urea plays a vital role in the excretory process by helping eliminate nitrogenous wastes from the body and maintaining proper physiological balance.
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.
Question 5 of 5
Why is nitrogen gas an extremely stable molecule?
Correct Answer: C
Rationale: The correct answer is C - triple covalent bonds. Nitrogen gas (N2) is composed of two nitrogen atoms held together by a triple covalent bond. This bond is very strong and requires a significant amount of energy to break, making nitrogen gas a stable molecule. Triple covalent bonds involve the sharing of three pairs of electrons, resulting in a very stable configuration. Resonance bonds, ionic bonds, and hydrogen bonds are not present in the structure of nitrogen gas, hence they do not contribute to its stability.