Nursing Elites

1. Where does cellular respiration, the process of converting chemical energy into ATP, take place in eukaryotic cells?

• A. Nucleus
• B. Ribosomes
• C. Mitochondria
• D. Golgi apparatus

Correct answer: C

Rationale: Cellular respiration, the process of converting chemical energy into ATP, takes place in the mitochondria of eukaryotic cells. The mitochondria are known as the powerhouse of the cell because they are responsible for generating most of the cell's ATP through the process of cellular respiration. This process involves the breakdown of glucose and other organic molecules to produce ATP, which is the primary energy currency of the cell. The other organelles listed in the options (nucleus, ribosomes, and Golgi apparatus) do not play a direct role in cellular respiration. The nucleus is responsible for storing genetic material, ribosomes are involved in protein synthesis, and the Golgi apparatus is involved in processing and packaging proteins for secretion or internal use.

2. Which cells myelinate neurons in the CNS?

• A. Schwann cells
• B. Astrocytes
• C. Microglia
• D. Oligodendrocytes

Correct answer: D

Rationale: The correct answer is D, Oligodendrocytes. Oligodendrocytes are responsible for myelinating neurons in the central nervous system (CNS). Schwann cells, found in the peripheral nervous system, are responsible for myelinating neurons there. Astrocytes support and maintain the neuronal environment, while microglia function as immune cells in the CNS, participating in immune responses and cellular debris clearance. Therefore, choices A, B, and C are incorrect for myelination of CNS neurons.

3. Which of the following represents the three main parts of a neuron?

• A. effector, cell body, axon
• B. dendrites, axon, cell body
• C. dendrites, axon, receptor
• D. synapse, axon, cell body

Correct answer: B

Rationale: A neuron consists of three main parts: dendrites, axon, and cell body. Dendrites receive signals from other neurons or sensory receptors. The cell body (soma) contains the nucleus and organelles essential for neuron function. The axon transmits electrical impulses away from the cell body to other neurons, muscles, or glands. Choice A is incorrect because an effector is not a part of a neuron. Choice C is incorrect because a receptor is not a component of a neuron but rather interacts with neurons. Choice D is incorrect because the synapse is a junction between neurons for signal transmission, not a structural part of a neuron.

4. Who is credited with the discovery of nuclear fission?

• A. Marie Curie
• B. Albert Einstein
• C. Enrico Fermi
• D. Ernest Rutherford

Correct answer: C

Rationale: Enrico Fermi is credited with the discovery of nuclear fission. In 1934, Fermi bombarded uranium with neutrons, leading to the splitting of the uranium nucleus and the release of energy. This groundbreaking discovery laid the foundation for the development of nuclear power and weapons. Marie Curie is known for her pioneering research on radioactivity, but she did not discover nuclear fission. Albert Einstein made significant contributions to physics, including the theory of relativity, but he was not credited with the discovery of nuclear fission. Ernest Rutherford conducted the famous gold foil experiment and made contributions to the understanding of the atom's structure, but he did not discover nuclear fission.

5. How do isotopes affect the atomic mass of an element?

• A. Isotopes have no effect on the atomic mass of an element.
• B. Isotopes cause the atomic mass of an element to vary slightly.
• C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
• D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since the atomic mass of an element is the weighted average of the masses of its isotopes, the presence of isotopes causes the atomic mass of an element to vary slightly. This variation occurs because different isotopes have different masses due to their varying numbers of neutrons. The atomic mass is affected by the abundance of each isotope, leading to a slight fluctuation in the overall atomic mass of the element. Choice A is incorrect because isotopes do influence the atomic mass. Choice C is incorrect because isotopes have different masses, affecting the overall atomic mass. Choice D is incorrect as isotopes typically do not cause a significant variation in atomic mass, but rather a slight fluctuation.

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