Nursing Elites

1. What happens to the wavelength of a wave when its frequency increases while the speed remains constant?

• A. Wavelength increases
• B. Wavelength decreases
• C. Wavelength remains the same
• D. Wavelength becomes zero

Correct answer: B

Rationale: When the speed of a wave is constant and the frequency increases, the wavelength must decrease to keep the speed constant. The speed of a wave is determined by the product of frequency and wavelength (speed = frequency x wavelength). If the frequency increases while the speed remains constant, the wavelength has to decrease proportionally to maintain the speed unchanged. Therefore, as the frequency increases, the wavelength decreases to ensure that the speed of the wave remains constant. Choice A is incorrect because as frequency increases, wavelength decreases. Choice C is incorrect as the wavelength cannot remain the same when frequency increases while speed is constant. Choice D is incorrect as the wavelength cannot become zero under these conditions.

2. 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.

3. Which valve prevents backflow into the atrium when the ventricles contract?

• A. Pulmonary valve
• B. Tricuspid valve
• C. Mitral valve
• D. Aortic valve

Correct answer: B

Rationale: The tricuspid valve (right atrioventricular valve) prevents backflow into the right atrium when the right ventricle contracts. This valve ensures that blood flows in the correct direction, preventing regurgitation into the atrium. The pulmonary valve is responsible for preventing backflow into the right ventricle from the pulmonary artery. The mitral valve prevents backflow into the left atrium, and the aortic valve prevents backflow into the left ventricle from the aorta. Therefore, the correct answer is the tricuspid valve as it specifically addresses the scenario of backflow into the atrium during ventricular contraction.

4. Which structure in the respiratory system is responsible for preventing food and liquids from entering the trachea during swallowing?

• A. Bronchi
• B. Larynx
• C. Alveoli
• D. Pharynx

Correct answer: B

Rationale: The larynx, housing the epiglottis, a flap of tissue, is the structure responsible for preventing food and liquids from entering the trachea during swallowing. It acts as a protective barrier, covering the trachea to ensure that ingested substances are directed to the esophagus. The bronchi are the primary airway passages that branch from the trachea into the lungs. Alveoli are tiny air sacs in the lungs where gas exchange occurs, facilitating the exchange of oxygen and carbon dioxide. The pharynx is the passage connecting the mouth and nasal cavity to the esophagus and trachea.

5. Which type of cell division is responsible for sexual reproduction?

• A. Mitosis
• B. Meiosis
• C. Amitosis
• D. Cytokinesis

Correct answer: B

Rationale: Meiosis is the type of cell division responsible for sexual reproduction. During meiosis, a single cell undergoes two rounds of division to produce four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is essential for sexual reproduction as it ensures that when two gametes (sperm and egg) combine during fertilization, the resulting zygote will have the correct number of chromosomes. Mitosis, on the other hand, is a type of cell division that produces two daughter cells with the same number of chromosomes as the parent cell and is involved in growth, repair, and asexual reproduction. Amitosis is a rare form of cell division that does not involve the typical processes of mitosis or meiosis. Cytokinesis is the process of dividing the cytoplasm of a cell after mitosis or meiosis.

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