Nokea
Which of the following illustrates a positive feedback mechanism?
- A. Maintaining blood pressure
- B. Uterine contractions during childbirth
- C. Body temperature control
- D. Control of blood sugar
Correct Answer: B
Rationale: The correct answer is uterine contractions during childbirth. This is an example of a positive feedback mechanism where the initial stimulus (contractions) leads to an increase in intensity and frequency, ultimately resulting in childbirth. In contrast, choices A, C, and D (maintaining blood pressure, body temperature control, and control of blood sugar) are examples of negative feedback mechanisms. These mechanisms work to maintain stability by counteracting any deviations from the set point, rather than amplifying the response like in a positive feedback mechanism.
You may also like to solve these questions
Ceroid pigments and lipofuscin accumulate with aging, impairing a cell's ability to withstand the damaging effects of oxygen free radicals.
- A. TRUE
- B. FALSE
- C. Not Sure
- D. None of the above
Correct Answer: A
Rationale: The statement provided in the question is true. Ceroid pigments and lipofuscin are products of cellular damage and aging. These substances accumulate within cells over time and can impair cellular functions, including the ability to withstand the damaging effects of oxygen free radicals. Choice B, 'False,' is incorrect because the accumulation of ceroid pigments and lipofuscin does indeed impair a cell's ability to deal with oxidative stress. Choices C and D are also incorrect as the statement is true.
Simple squamous epithelium is an example of a(n)
- A. organ system.
- B. organ.
- C. tissue.
- D. molecule.
Correct Answer: C
Rationale: Simple squamous epithelium is a type of tissue, not an organ system, organ, or molecule. Tissues are groups of cells that work together to perform a specific function. In this case, simple squamous epithelium is a thin, single layer of flattened cells that line surfaces involved in passive diffusion, such as the alveoli in the lungs or blood vessels. Therefore, the correct answer is 'tissue.' Choices A, B, and D are incorrect as they do not accurately categorize simple squamous epithelium as a tissue.
Maintaining a stable internal environment typically requires
- A. positive feedback mechanisms.
- B. an unstable outside environment.
- C. decreased atmospheric pressure.
- D. negative feedback mechanisms.
Correct Answer: D
Rationale: The correct answer is 'negative feedback mechanisms.' In biological systems, negative feedback mechanisms help maintain homeostasis by counteracting any deviations from the set point. They work to stabilize internal conditions and keep them within a narrow range. On the other hand, positive feedback mechanisms amplify changes and are not involved in maintaining stability. Choice B, 'an unstable outside environment,' is incorrect as internal stability is independent of external conditions like weather. Choice C, 'decreased atmospheric pressure,' is also incorrect as it does not directly relate to internal homeostasis.
Is the following statement true: The anatomical position is lying down, as a cadaver would be positioned?
- A. TRUE
- B. FALSE
- C. Not Sure
- D. None of the above
Correct Answer: B
Rationale: The correct answer is False. The anatomical position is a standardized way of describing the human body's orientation in a consistent manner. The anatomical position is standing upright, facing forward, with the arms at the sides and palms facing forward. This position serves as a reference point for anatomical descriptions and directional terms. Therefore, the statement that the anatomical position is lying down, as a cadaver would be positioned, is incorrect. Choice A is incorrect because the anatomical position is not lying down. Choices C and D are also incorrect as there is a definitive answer to the question.
Do patterns of growth in preserved bones and tooth decay reflect the health of the people they were a part of?
- A. Yes
- B. No
- C. Not enough information to determine
- D. Not applicable
Correct Answer: A
Rationale: Patterns of growth in preserved bones and tooth decay can indeed reflect the health of the individuals they belonged to. Growth patterns can indicate malnutrition or diseases during childhood, while tooth decay can signify dietary habits and overall health. Therefore, the correct answer is 'Yes.' 'No' is incorrect because these factors can provide valuable information about the health of individuals. 'Not enough information to determine' is incorrect as these indicators are commonly used in anthropological and archaeological studies to understand health conditions in past populations. 'Not applicable' is also incorrect as the information from bones and tooth decay is relevant to assessing the health of individuals.