Nursing Elites

1. Within a nuclear reactor, control rods serve the primary purpose of:

• A. Reflecting neutrons back into the core
• B. Absorbing excess neutrons to control criticality
• C. Moderating the velocity of neutrons
• D. All of the above

Correct answer: C

Rationale: Control rods within a nuclear reactor serve the primary purpose of absorbing excess neutrons to control criticality. By adjusting the position of the control rods, the reactor operators can regulate the rate of fission reactions and prevent the reactor from overheating or reaching a state of uncontrolled chain reaction. Reflecting neutrons back into the core and moderating the velocity of neutrons are not the primary functions of control rods. Reflectors are used to bounce neutrons back into the core, while moderators slow down fast neutrons to increase the likelihood of fission. Therefore, the correct answer is B: 'Absorbing excess neutrons to control criticality.'

2. During which stage of meiosis II are sister chromatids separated, resulting in four genetically unique daughter cells?

• A. Prophase I
• B. Prophase II
• C. Anaphase I
• D. Anaphase II

Correct answer: D

Rationale: Rationale: - Prophase I occurs in meiosis I, not meiosis II. During Prophase I, homologous chromosomes pair up and exchange genetic material in a process called crossing over. - Prophase II is the stage where the nuclear envelope breaks down, and spindle fibers start to reappear, preparing the cell for division. Sister chromatids are still attached during Prophase II. - Anaphase I is the stage in meiosis I where homologous chromosomes are separated and pulled to opposite poles of the cell. - Anaphase II is the stage in meiosis II where sister chromatids are separated and pulled to opposite poles of the cell, resulting in four genetically unique daughter cells. This is the stage where the final separation of genetic material occurs, leading to the formation of haploid daughter cells.

3. The stratified squamous epithelium found in the skin is adapted for:

• A. Absorption
• B. Secretion
• C. Protection
• D. Gas exchange

Correct answer: C

Rationale: The correct answer is C: Protection. Stratified squamous epithelium is a type of tissue that is well-suited for protection as it consists of multiple layers of cells that provide a barrier against physical and chemical damage. In the skin, this epithelium helps protect the body against external threats such as pathogens, UV radiation, and mechanical abrasion. Absorption (A) and secretion (B) are typically functions of other types of epithelial tissues, such as simple columnar or simple cuboidal epithelium. Gas exchange (D) is primarily facilitated by tissues like the alveolar epithelium in the lungs, not stratified squamous epithelium in the skin.

4. Electrons occupy specific energy levels around the nucleus with varying probabilities. The electron cloud 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: B

Rationale: 2 filled s orbitals and 6 filled p orbitals. This notation indicates two electrons in the 2s orbital and six electrons in the 2p orbitals.

5. Which of the following is NOT a function of the skeletal system?

• A. Support and structure
• B. Production of red blood cells
• C. Storage of minerals like calcium
• D. Insulation of the body

Correct answer: A

Rationale: The correct answer is A. The skeletal system provides support and structure to the body, allowing for movement and protecting internal organs. The production of red blood cells occurs in the bone marrow, which is a function of the skeletal system. Additionally, the skeletal system stores minerals like calcium, which play a crucial role in bone health and overall bodily functions. Insulation of the body is not a primary function of the skeletal system but is rather a function of adipose tissue and the integumentary system. Therefore, option A is the correct answer as it does not align with the functions of the skeletal system.

6. Which process involves the body's natural defense against inhaled dust and allergens?

• A. Cellular respiration
• B. Gas exchange
• C. Ciliary action
• D. Bronchoconstriction

Correct answer: C

Rationale: The correct answer is C: Ciliary action. Cilia are tiny hair-like structures lining the respiratory tract that help trap and remove inhaled dust and allergens. When these particles are trapped in the mucus produced by the cilia, the cilia beat in a coordinated fashion to move the mucus and its trapped particles out of the respiratory system, preventing them from reaching the lungs. Cellular respiration (A) is the process by which cells generate energy from nutrients, not a defense mechanism. Gas exchange (B) refers to the exchange of oxygen and carbon dioxide in the lungs, not a defense mechanism. Bronchoconstriction (D) is the narrowing of the airways, often in response to triggers like allergens, but it is not the body's natural defense mechanism against inhaled dust and allergens.

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