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What is the SI unit of measurement for work?
- A. Newton-meter (N·m)
- B. Joule (J)
- C. Watt (W)
- D. Meter per second (m/s)
Correct Answer: B
Rationale: The correct answer is B: Joule (J). Work is defined as the amount of energy transferred by a force acting through a distance. The Joule is the unit used to measure this energy transfer. Choice A, Newton-meter (N·m), is the unit for torque, not work. Choice C, Watt (W), is the unit of power, not work. Choice D, Meter per second (m/s), is a unit for speed or velocity and is not related to work.
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What is the function of ribosomes?
- A. Packaging and transporting proteins
- B. Storing genetic material
- C. Controlling cell division
- D. Synthesizing proteins
Correct Answer: D
Rationale: The correct answer is D: Synthesizing proteins. Ribosomes are cellular organelles responsible for protein synthesis. They read the messenger RNA (mRNA) and utilize the information to assemble amino acids into proteins through a process known as translation. Choice A, packaging and transporting proteins, is incorrect as this function is typically performed by the Golgi apparatus and vesicles. Choice B, storing genetic material, is incorrect as genetic material is usually stored in the nucleus in the form of DNA. Choice C, controlling cell division, is incorrect as this function is primarily regulated by the cell cycle checkpoints and specific proteins involved in cell cycle regulation.
What is the atomic number of an element?
- A. The number of protons in an atom's nucleus.
- B. The number of neutrons in an atom's nucleus.
- C. The number of electrons in an atom's valence shell.
- D. The number of isotopes of an element.
Correct Answer: A
Rationale: The atomic number of an element is the number of protons in an atom's nucleus. This number is crucial as it determines the element's identity and its position on the periodic table. Option B is incorrect because the number of neutrons can vary in isotopes but is not the atomic number. Option C is incorrect as the number of electrons in an atom's valence shell can vary based on the element's charge, not defining the atomic number. Option D is also incorrect because the number of isotopes is not the atomic number of an element.
Why do emerging infectious diseases (EIDs) pose a significant public health threat?
- A. Because they are well-understood by medical professionals
- B. Because they are easily treatable with existing antibiotics
- C. Because they are new, rapidly evolving, and can spread quickly
- D. Because they primarily affect animals and not humans
Correct Answer: C
Rationale: Emerging infectious diseases (EIDs) are a significant public health threat because they are characterized by being new or newly identified diseases that are rapidly evolving. These diseases can spread quickly within populations due to factors such as globalization, travel, urbanization, and changes in climate. EIDs often present challenges to medical professionals as they may not be well-understood initially, making it difficult to develop effective treatments or preventive measures. While some EIDs can be treatable with existing antibiotics, the rapid evolution of these diseases can lead to the development of drug resistance, further complicating treatment efforts. Additionally, EIDs are not limited to affecting animals; they can also have serious implications for human health and well-being. Therefore, the correct answer is that EIDs pose a threat because they are new, rapidly evolving, and can spread quickly. Choices A, B, and D are incorrect because EIDs are not well-understood initially, may develop drug resistance, and can affect humans significantly, not just animals.
Which type of cartilage allows for smooth movement at joints and absorbs shock?
- A. Hyaline cartilage
- B. Fibrocartilage
- C. Elastic cartilage
- D. None of the above
Correct Answer: B
Rationale: Fibrocartilage is the correct answer. It is found in areas requiring both support and resilience, such as the intervertebral discs and knee joints. Fibrocartilage contains collagen fibers for strength and proteoglycans for resilience, making it suitable for functions that involve smooth movement at joints and shock absorption. Hyaline cartilage, while providing structural support, is not primarily responsible for smooth movement and shock absorption. Elastic cartilage is more flexible and is found in locations like the ear and epiglottis, but it is not known for its shock-absorbing properties. Choosing 'None of the above' disregards the correct option of fibrocartilage, which is specifically designed for the functions described in the question.
What is the formula to calculate kinetic energy?
- A. Kinetic Energy = Mass Velocity
- B. Kinetic Energy = Force Distance
- C. Kinetic Energy = Power Time
- D. Kinetic Energy = Potential Energy · Time
Correct Answer: A
Rationale: Kinetic energy is the energy an object possesses due to its motion. The formula to calculate kinetic energy is KE = 0.5 mass velocity^2, which can also be written as KE = mass (velocity)^2. Therefore, the correct formula is Kinetic Energy = Mass Velocity. Choice B is incorrect because it represents the work formula. Choice C is incorrect as it represents the formula for work done. Choice D is incorrect as it does not accurately represent the formula for calculating kinetic energy.