Nokea
Which of the following best describes a blood clot stimulating further clotting?
- A. a positive feedback mechanism.
- B. a negative feedback mechanism.
- C. a process turning itself off.
- D. nervous system communication
Correct Answer: A
Rationale: A blood clot stimulating further clotting is an example of a positive feedback mechanism. In positive feedback, the response enhances or amplifies the original stimulus, leading to an increase in the activity. In this case, the formation of a blood clot triggers more clotting activity, creating a cycle of increasing clot formation. Negative feedback mechanisms, on the other hand, work to maintain homeostasis by counteracting changes. Choices B, C, and D are incorrect as they do not accurately describe the situation of a blood clot stimulating further clotting.
You may also like to solve these questions
Are kidneys part of the lymphatic system?
- A. TRUE
- B. FALSE
- C. Not Sure
- D. None of the above
Correct Answer: B
Rationale: The correct answer is False. Kidneys are not part of the lymphatic system; they are part of the urinary system. The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. Therefore, choices A, C, and D are incorrect because kidneys are not associated with the lymphatic system.
A parietal layer of a serous membrane lines cavities, whereas a visceral layer of a serous membrane covers organs.
- A. covers organs; lines cavities
- B. lines cavities; covers organs
- C. secretes serous fluid; secretes mucus
- D. secretes mucus; secretes a serous fluid
Correct Answer: B
Rationale: In serous membranes, the parietal layer lines the cavities, providing support and protection, while the visceral layer covers the organs, reducing friction and allowing them to move freely. Therefore, the correct answer is 'lines cavities; covers organs.' Choices C and D are incorrect because serous membranes do not secrete mucus; instead, they secrete a watery serous fluid. Choice A is incorrect as it reverses the functions of the parietal and visceral layers in relation to organs and cavities.
The activities of an anatomist consist of ______, whereas those of a physiologist consist of _____.
- A. observing body parts; studying functions of body parts
- B. conducting experiments; making microscopic examinations
- C. studying molecules; observing forms of the body parts
- D. sketching; dissecting
Correct Answer: A
Rationale: An anatomist focuses on observing the structure and morphology of body parts, such as organs, tissues, and cells, to understand their organization. On the other hand, a physiologist is more concerned with studying the functions and processes of these body parts, including how they work individually and together to maintain homeostasis. Therefore, the correct answer is 'observing body parts; studying functions of body parts.' Choices B, C, and D are incorrect as they do not accurately reflect the primary activities of anatomists and physiologists.
What is assimilation?
- A. changing absorbed substances into different chemical forms
- B. breaking down foods into nutrients that the body can absorb
- C. eliminating waste from the body
- D. an increase in body size without a change in overall shape
Correct Answer: A
Rationale: Assimilation is the process of changing absorbed substances into different chemical forms. It occurs after nutrients from food are absorbed into the bloodstream and used by the body. Choice B, breaking down foods into nutrients that the body can absorb, refers to the process of digestion rather than assimilation. Choice C, eliminating waste from the body, describes the process of excretion. Choice D, an increase in body size without a change in overall shape, does not accurately define assimilation.
What do positive feedback mechanisms do?
- A. Cause long-term changes.
- B. Move conditions away from the normal state.
- C. Bring conditions back to the normal state.
- D. Usually produce stable conditions.
Correct Answer: B
Rationale: Positive feedback mechanisms amplify or increase changes in a system, moving conditions away from the normal state. This makes choice B the correct answer. Choice A is incorrect as positive feedback does not cause long-term changes but rather accelerates deviations from the norm. Choice C is incorrect because positive feedback does not bring conditions back to normal; instead, it amplifies deviations. Choice D is incorrect as positive feedback does not usually lead to stable conditions but rather to further deviations from the normal state.