metabolism is defined as

ATI RN

ATI Anatomy and Physiology Online Practice

1. Metabolism is defined as _____.

A. the removal of wastes produced by chemical reactions
B. the breakdown of substances into simpler forms
C. the taking in of nutrients
D. all the chemical reactions occurring in an organism that support life

Correct answer: D

Rationale: Metabolism refers to all the chemical reactions that take place within an organism to sustain life, including processes such as breaking down molecules, building new molecules, and energy production. Choice A is incorrect because it describes excretion rather than metabolism. Choice B is incorrect as it specifically refers to the breakdown of substances, not encompassing the entirety of metabolic processes. Choice C is incorrect as it focuses solely on nutrient intake, which is just one aspect of metabolism.

2. The recent discovery of taste receptors that detect sweetness in the small intestine illustrates that

A. chemical responses occur in various parts of the body.
B. new discoveries about anatomy and physiology are still being made.
C. everything about anatomy and physiology has been discovered.
D. the molecular and cellular level is crucial in anatomy and physiology.

Correct answer: B

Rationale: The recent discovery of taste receptors in the small intestine illustrates that new discoveries about anatomy and physiology are still being made. This finding demonstrates that our understanding of the human body is continuously evolving. Choice A is incorrect because the discovery does not imply that chemical responses occur in only one part of the body but rather showcases a specific new discovery. Choice C is incorrect as it is highly improbable that everything about anatomy and physiology has been discovered given the complexity of the human body. Choice D is incorrect as while the molecular and cellular level is important in anatomy and physiology, the primary focus of this discovery is on the new findings about the taste receptors in the small intestine.

3. The removal of wastes produced by metabolic reactions is

A. metabolism.
B. absorption.
C. assimilation.
D. excretion.

Correct answer: D.

Rationale: The correct answer is 'excretion.' Excretion is the process of eliminating waste products produced by metabolic reactions from the body. Metabolism (Choice A) refers to the chemical processes that occur within a living organism to maintain life. Absorption (Choice B) is the process of taking in nutrients and fluids into the body. Assimilation (Choice C) is the process of absorbing and incorporating nutrients into the body after digestion. Therefore, excretion is the most appropriate term for the removal of metabolic wastes.

4. One characteristic that centenarians share is

A. a high level of exercise throughout life
B. long-lived relatives
C. following the Mediterranean diet
D. never having smoked

Correct answer: D

Rationale: The correct answer is 'never having smoked.' Research suggests that one of the common characteristics among centenarians is that they have never smoked. Smoking is a well-known risk factor for various diseases and can significantly reduce lifespan. Choice A, 'a high level of exercise throughout life,' is not a universal characteristic among centenarians, although exercise can contribute to a healthy lifestyle. Choice B, 'long-lived relatives,' while genetics can play a role in longevity, not all centenarians have long-lived relatives. Choice C, 'following the Mediterranean diet,' is a healthy dietary choice but not a defining characteristic shared by all centenarians.

5. Is a cell the basic unit of structure and function of an organism?

A. True
B. False
C. Not Sure
D. None of the above

Correct answer: A

Rationale: The correct answer is A: True. A cell is indeed the basic unit of structure and function of an organism. Cells are the smallest independently functioning unit in the structure of an organism and carry out vital functions necessary for life. Choice B, False, is incorrect because cells are universally recognized as the fundamental unit of life. Choice C, Not Sure, is incorrect as the role of a cell as the basic unit of an organism's structure and function is a well-established scientific fact. Choice D, None of the above, is incorrect as the statement provided in the question is true.