ATI TEAS Science Test

Correct Answer: A

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction to occur, lowering the activation energy needed for the reaction to proceed. As a result, more reactant molecules can overcome this energy barrier and participate in the reaction, leading to a faster overall reaction rate. This explanation contradicts choices B, C, and D as a catalyst does not slow down, reverse, or prevent a reaction; instead, it accelerates the reaction by facilitating a more efficient route for the reaction to take place. Therefore, the correct answer is that a catalyst speeds up the reaction.

Correct Answer: A

Rationale: Weight is correctly identified as an extensive property. Extensive properties are dependent on the amount of the substance present. Weight is directly proportional to the quantity of the substance, making it an extensive property. In contrast, density, conductivity, and malleability are intensive properties, which remain constant regardless of the amount of substance. Therefore, the correct answer is 'Weight' as it changes with the quantity of the substance, aligning with the definition of an extensive property.

Correct Answer: B

Rationale: The corrected question focuses on the consequence of bone marrow failure, which is pancytopenia. Bone marrow failure results in decreased production of red blood cells, white blood cells, and platelets, leading to pancytopenia. This condition manifests as fatigue, weakness, increased infection susceptibility, and bleeding tendencies. Paraplegia, seizures, and pathologic fractures are not typical outcomes of bone marrow failure. Paraplegia is associated with spinal cord injury, seizures with neurological disorders, and pathologic fractures with conditions like osteoporosis or bone tumors.

Correct Answer: B

Rationale: The correct answer is B. The process of coagulation, also known as blood clotting, begins instantly after a blood vessel has been damaged. When a blood vessel is injured, the body quickly responds by initiating a cascade of reactions to form a blood clot, which helps to stop bleeding and promote healing. Choices A, C, and D are incorrect because coagulation does not occur just when blood changes from a gel to liquid form, it is not a response of blood drying upon contact with air, and it is not simply the formation of fibrin. The primary trigger for coagulation is vascular injury.

Correct Answer: C

Rationale: Using a computer does not eliminate all subjectivity and potential bias from an experiment. While computers can assist in data collection and analysis, the design and execution of the research study can still be influenced by subjectivity and bias introduced by researchers. Researchers need to recognize their potential biases and take measures to reduce them throughout the research process. Choice A is correct as computers are valuable for managing large datasets. Choice B is correct as computers can efficiently work with instruments and record data. Choice D is correct as computers excel in performing complex calculations faster and more accurately than humans.