Nokea
Which of the following quantities do catalysts alter to control the rate of a chemical reaction?
- A. Substrate energy
- B. Activation energy
- C. Inhibitor energy
- D. Promoter energy
Correct Answer: B
Rationale: The correct answer is B: Activation energy. Catalysts function by reducing the activation energy needed for a chemical reaction to proceed. By lowering the activation energy, catalysts facilitate the reaction without being consumed themselves. Substrate energy, inhibitors, and promoters are not directly altered by catalysts in the same way activation energy is. Substrate energy refers to the energy of the reactants, which is not altered by catalysts. Inhibitors increase the activation energy required for a reaction, while promoters enhance the effectiveness of a catalyst but do not represent a quantity altered by catalysts.
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A researcher wants to investigate the relationship between family income and quality of medical care. Which statement provides the best reason to conduct this investigation?
- A. The researcher can identify affordable medical care to recommend to low-income families.
- B. The investigation can help identify individuals who are healthy so they can maintain their health.
- C. Results of this investigation may identify a group of people who do not receive quality medical care and could benefit from improved medical treatments.
- D. There is a valid reason to conduct this investigation.
Correct Answer: C
Rationale: The correct answer is C because identifying a group of individuals who do not receive quality medical care can lead to targeted interventions to improve their access to better medical treatments. This investigation can help address disparities in healthcare and improve outcomes for those in need. Choice A is incorrect because the focus is on identifying those who lack quality medical care, not just affordable care. Choice B is incorrect as it misinterprets the purpose of the investigation, which is to improve medical care for those not receiving quality care, rather than maintaining the health of those already healthy. Choice D is too vague and does not provide a specific reason for conducting the investigation, unlike choice C which highlights the potential benefits of identifying individuals in need of improved medical treatments.
Which of the following best describes a function carried out by the circulatory system and the integumentary system working together?
- A. Removal of excess heat from the body
- B. Hormonal regulation of blood pressure
- C. Transport of oxygen in the body
- D. Production of red blood cells in the bone marrow
Correct Answer: A
Rationale: The correct answer is A: Removal of excess heat from the body. The circulatory system, which includes blood vessels and the heart, works with the integumentary system, which consists of the skin, to regulate body temperature by removing excess heat. This process involves blood vessels near the skin's surface dilating to release heat and constricting to conserve heat, a mechanism crucial for maintaining homeostasis. Option B, Hormonal regulation of blood pressure, is incorrect as it does not accurately describe the collaborative function of these systems in regulating body temperature. Option C, Transport of oxygen in the body, is incorrect as it focuses on a different function of the circulatory system. Option D, Production of red blood cells in the bone marrow, is incorrect as it pertains to the skeletal and hematopoietic systems, not the circulatory and integumentary systems working together to regulate body temperature.
Which organelle provides energy for cellular functions?
- A. Nucleus
- B. Cell membrane
- C. Mitochondria
- D. Cytoplasm
Correct Answer: C
Rationale: The correct answer is C, Mitochondria. Mitochondria are often referred to as the powerhouse of the cell as they produce energy in the form of ATP through cellular respiration. This process is essential for various cellular functions, making mitochondria crucial for energy production within the cell. Choice A, Nucleus, is incorrect as the nucleus is responsible for housing the cell's genetic material and controlling cellular activities but not for energy production. Choice B, Cell membrane, is incorrect as it is primarily involved in maintaining cell integrity and regulating the passage of substances in and out of the cell, not in energy production. Choice D, Cytoplasm, is incorrect as it is the jelly-like substance that fills the cell and is the site of many metabolic pathways, but it is not the specific organelle responsible for energy production.
Which of the following blood vessels contains the least oxygenated blood?
- A. Aorta
- B. Vena cava
- C. Pulmonary artery
- D. Femoral vein
Correct Answer: C
Rationale: The correct answer is C: Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This blood is considered the least oxygenated in the body as it has just returned from circulating through the body's tissues and is in need of oxygen replenishment. Choice A, the aorta, is incorrect as it carries oxygenated blood from the heart to the rest of the body. Choice B, the vena cava, carries deoxygenated blood from the body back to the heart. Choice D, the femoral vein, also carries deoxygenated blood back to the heart from the lower extremities.
How do DNA and RNA function together as part of the human genome?
- A. DNA carries genetic information from RNA to the cell cytoplasm.
- B. RNA carries genetic information from DNA to the cell cytoplasm.
- C. DNA and RNA carry genetic information from the cell nucleus to the cytoplasm.
- D. DNA and RNA do not interact within the cell.
Correct Answer: B
Rationale: The correct answer is B. RNA acts as a messenger carrying genetic instructions from the DNA in the nucleus to the cytoplasm, where proteins are synthesized. This process is known as transcription and translation, where DNA provides the blueprint for protein synthesis, and RNA delivers this information to the cellular machinery in the cytoplasm. Choice A is incorrect as it inaccurately states that DNA carries genetic information from RNA, which is the opposite of the actual flow of information. Choice C is incorrect as it suggests that both DNA and RNA together carry genetic information from the nucleus to the cytoplasm, which is not accurate. Choice D is incorrect as DNA and RNA do interact within the cell, playing crucial roles in genetic information processing and protein synthesis.