Nursing Elites

1. In the electron cloud model, electrons occupy specific energy levels around the nucleus with varying probabilities. This model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.

• A. 2 protons and 6 neutrons
• B. 2 filled s orbitals and 6 filled p orbitals
• C. 2s orbitals with 2 and 6 electrons, respectively
• D. 4 filled electron shells

Correct answer: C

Rationale: The electron cloud model describes electrons existing in distinct energy levels, not fixed orbits. Option C correctly describes the electron configuration of an atom with 2s orbitals containing 2 electrons and 6 electrons in the 2p orbitals. This configuration aligns with the electron cloud model where electrons are found in specific energy levels with varying probabilities. Options A, B, and D do not accurately represent the electron cloud model.

2. What information does a genotype provide that a phenotype does not?

• A. The genotype necessarily includes the proteins coded for by its alleles.
• B. The genotype will always display an organism's recessive alleles.
• C. The genotype must include the organism's physical characteristics.
• D. The genotype indicates what an organism's parents looked like.

Correct answer: A

Rationale: The genotype provides information about the specific genetic makeup of an organism, including the alleles it possesses for a particular trait. This information is not always directly reflected in the phenotype, which is the observable physical characteristics of an organism. The genotype determines the proteins coded for by its alleles, but the phenotype is the expression of those proteins in the organism's traits. Therefore, the genotype necessarily includes the proteins coded for by its alleles, a detail not provided solely by the phenotype.\nChoice B is incorrect because the genotype may include dominant alleles as well, not just recessive ones. Choice C is incorrect because the genotype refers to genetic information, not physical characteristics. Choice D is incorrect because the genotype does not directly indicate what an organism's parents looked like; it primarily describes the genetic information inherited from parents.

3. What is a temporary loss of consciousness due to insufficient blood flow to the brain called?

• A. Stroke
• B. Seizure
• C. Syncope (fainting)
• D. Coma

Correct answer: C

Rationale: Syncope, also known as fainting, is a temporary loss of consciousness caused by insufficient blood flow to the brain. It results from a brief interruption in the brain's blood supply, leading to a temporary loss of consciousness. The correct answer is C. A stroke, option A, is caused by a blockage or rupture of blood vessels in the brain, not insufficient blood flow. Seizure, option B, involves a sudden surge of electrical brain activity, not reduced blood flow. Coma, option D, is characterized by prolonged unconsciousness, not a temporary loss of consciousness due to insufficient blood flow.

4. Which organ of the body compensates when a person's intake of vitamins decreases?

• A. Appendix
• B. Liver
• C. Pancreas
• D. Stomach

Correct answer: B

Rationale: The liver is the organ that compensates when a person's intake of vitamins decreases. It stores certain vitamins, such as vitamins A, D, E, K, and B12, and releases them when dietary intake decreases. This helps maintain the body's vitamin levels and functions. The other organs listed - Appendix, Pancreas, and Stomach - do not primarily play a role in compensating for a decrease in vitamin intake. The liver is crucial in maintaining vitamin balance, making it the correct choice in this context.

5. 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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