When does cell death first occur?
- A. At age 60.
- B. At age 50.
- C. At puberty.
- D. In the fetus.
Correct Answer: D
Rationale: Cell death, also known as apoptosis, first occurs during fetal development when specific cells are programmed to die. This process is essential for shaping and organizing tissues and organs. Choices A, B, and C are incorrect because cell death begins much earlier, during fetal development, rather than later in life or at puberty. Understanding the timing of cell death in different stages of life is crucial in developmental biology.
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Is the elbow distal to the wrist?
- A. TRUE
- B. FALSE
- C. Not Sure
- D. None of the above
Correct Answer: B
Rationale: The correct answer is False. In anatomical terms, 'distal' means farther away from the center of the body or the point of attachment. The elbow is proximal to the wrist because it is closer to the center of the body. Therefore, the statement that the elbow is distal to the wrist is incorrect. Choice A is incorrect because the elbow is not distal to the wrist. Choice C is incorrect as the anatomical relationship between the elbow and wrist can be determined. Choice D is incorrect as there is a definitive answer to this anatomical question.
Living organisms use oxygen to __________________.
- A. reduce heat production
- B. accept electrons for cellular metabolism
- C. release energy stored in the molecules of food
- D. remove metabolic wastes
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.
Specialized cell types organized in a way that provides a specific function form
- A. tissues, which build organs.
- B. organs, which build tissues.
- C. organ systems, which build tissues.
- D. atoms, which comprise tissues.
Correct Answer: A
Rationale: The correct answer is 'tissues, which build organs.' Specialized cell types organize to form tissues, which in turn build organs. Tissues are groups of cells that work together to perform a specific function. Option B is incorrect because organs are composed of tissues, not the other way around. Option C is incorrect as organ systems consist of multiple organs working together, not building tissues. Option D is incorrect as atoms are the basic building blocks of matter and are not directly involved in forming tissues.
What is the membrane on the surface of a lung called?
- A. visceral pleura
- B. parietal pleura
- C. visceral pericardium
- D. parietal pericardium
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.
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.