Living organisms use oxygen to __________________.

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: C

Rationale: Reproduction is the most important process for the continuation of the human species as it involves the creation of new individuals. Without reproduction, the human species would cease to exist. Responsiveness and movement are essential for individual survival and functioning but do not directly impact the continuation of the species. Respiration is crucial for obtaining energy but is not directly linked to the continuation of the species.

Correct Answer: C

Rationale: The correct answer is 'superior to.' The thoracic cavity is located above the abdominopelvic cavity, making it superior. The term 'dorsal (posterior) to' refers to the back side, 'ventral (anterior) to' indicates the front side, and 'inferior to' means below. In the context of body cavities, the thoracic cavity is positioned higher than the abdominopelvic cavity, making 'superior to' the most appropriate choice.

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: B

Rationale: Magnetic resonance imaging, commonly known as MRI, is a non-invasive imaging technique used to visualize internal structures of the body. While it can be used to distinguish between normal and abnormal tissue, one of its common applications is to examine musculoskeletal injuries, such as an injured knee. Choice A has been corrected to mention 'normal and abnormal tissue' instead of 'normal and cancerous tissue' as MRI is not solely used for cancer detection. Choice C is incorrect as MRI can provide detailed images of various body parts, not just limited to the brain. Therefore, the correct answer is to examine an injured knee.

Correct Answer: A

Rationale: The correct answer is A: visceral pleura. The membrane covering the surface of the lungs is called the visceral pleura. It is a serous membrane that is in direct contact with the lung tissue. Choices B, C, and D are incorrect because the parietal pleura covers the inner surface of the chest wall and diaphragm, the visceral pericardium covers the surface of the heart, and the parietal pericardium is the outer layer of the pericardium surrounding the heart, respectively.

Correct Answer: B

Rationale: The correct answer is False. The oral, nasal, orbital, and middle ear cavities are actually part of the ventral cavity, not the dorsal cavity. The dorsal cavity contains the cranial and spinal cavities, while the ventral cavity includes the thoracic, abdominal, and pelvic cavities. Therefore, these structures are located in the ventral cavity, not the dorsal cavity. Choices A, C, and D are incorrect because these structures are not situated in the dorsal cavity.

Correct Answer: C

Rationale: The correct answer is C: Absorption of nutrients. The main function of the digestive system is to break down food into nutrients that can be absorbed by the body. Choice A, 'Formation of cells,' is incorrect as cell formation is not the primary function of the digestive system. Choice B, 'Movement of body parts,' is incorrect as this is more related to the muscular system. Choice D, 'Providing oxygen for the extraction of energy from nutrients,' is incorrect because providing oxygen is primarily the function of the respiratory system, not the digestive system.

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.