ATI Anatomy and Physiology Online Practice

Correct Answer: C

Rationale: Positive feedback mechanisms usually result in unstable conditions. In a positive feedback loop, the output enhances or amplifies the changes that are occurring, leading to a deviation from the initial set point. Therefore, positive feedback does not bring values back towards the set point (Choice A). Choice B is incorrect because positive feedback does not promote stability around a set point. Choice D is also incorrect as positive feedback mechanisms typically do not lead to long-term changes; instead, they intensify the initial change, causing instability.

Correct Answer: A

Rationale: The statement is true. Temperature is a measure of the average kinetic energy of the particles in a substance, while heat is the transfer of energy from a hotter object to a colder one. Heat is not a measurement of the intensity of temperature, but rather the energy transfer due to a temperature difference. Therefore, the correct answer is True. Choice B (False) is incorrect as the statement is true based on the definitions of temperature and heat.

Correct Answer: C

Rationale: The correct answer is C. Living organisms use oxygen to release energy stored in the molecules of food through a process called cellular respiration. This process involves breaking down glucose molecules in the presence of oxygen to produce energy in the form of ATP. Choice A is incorrect because oxygen does not directly reduce heat production in organisms. Choice B is incorrect because oxygen is involved in accepting electrons rather than donating them in cellular metabolism. Choice D is incorrect because the removal of metabolic wastes is not the primary role of oxygen in living organisms.

Correct Answer: B

Rationale: Chromosomes do not get longer as a cell ages. In fact, chromosomes condense and become more compact during cell division to ensure proper segregation. Choice A is incorrect because chromosomes do not elongate with age. Choice C is not the correct answer as there is scientific evidence to support that chromosomes do not lengthen over time. Choice D is not the right option as the correct answer is 'False' in this case.

Correct Answer: D

Rationale: The correct answer is D: Circulation-the movement of substances in body fluids. Circulation refers to the movement of substances like nutrients, gases, and wastes in body fluids to and from cells. Choice A is incorrect because responsiveness is about detecting and responding to changes in the environment, not obtaining and using oxygen. Choice B is incorrect because assimilation is the process of incorporating absorbed substances into the body, not changing them into chemically different forms. Choice C is incorrect because respiration is the process of obtaining energy from food molecules through oxygen, not the obtaining and using oxygen itself.