Nursing Elites

1. During vigorous exercise, why does the respiratory rate increase?

• A. Meet the increased demand for oxygen in working muscles
• B. Eliminate excess carbon dioxide more slowly
• C. Conserve energy for physical activity
• D. Decrease the amount of oxygen delivered to the body

Correct answer: A

Rationale: During vigorous exercise, the muscles require more oxygen to produce energy for physical activity. The increased respiratory rate helps to deliver more oxygen to the working muscles to meet this demand. This process is essential for sustaining physical activity and preventing fatigue. Choice A is the correct answer as it accurately describes the purpose of the increased respiratory rate during vigorous exercise. Choices B, C, and D are incorrect. Choice B, 'Eliminate excess carbon dioxide more slowly,' is inaccurate as the primary reason for the increased respiratory rate during exercise is to meet the increased demand for oxygen, not to eliminate carbon dioxide. Choice C, 'Conserve energy for physical activity,' is incorrect because increasing the respiratory rate actually expends energy to meet the oxygen demand of the working muscles. Choice D, 'Decrease the amount of oxygen delivered to the body,' is incorrect as the increased respiratory rate is specifically to deliver more oxygen to the body during exercise.

2. Endotoxins are toxic substances released by:

• A. Viruses
• B. Bacteria (gram-positive)
• C. Bacteria (gram-negative)
• D. Parasites

Correct answer: C

Rationale: Endotoxins are toxic substances that are part of the outer membrane of the cell wall of gram-negative bacteria. These toxins are released when the bacteria are destroyed or during bacterial growth. Endotoxins can cause a variety of harmful effects in the host, including fever, inflammation, and septic shock. Viruses do not produce endotoxins; they are typically associated with producing viral proteins that can be toxic to host cells. Gram-positive bacteria produce exotoxins, which are different from endotoxins found in gram-negative bacteria. Parasites, though capable of causing diseases, are not typically associated with the production of endotoxins.

3. Which of the following factors does NOT affect the rate of dissolution of a solute in a solvent?

• A. Temperature
• B. Pressure
• C. Surface area
• D. Particle size

Correct answer: B

Rationale: Pressure does not affect the rate of dissolution of a solute in a solvent. The factors that affect the rate of dissolution include temperature, surface area, and particle size. Temperature generally increases the rate of dissolution by providing more energy for the solute particles to break apart and mix with the solvent. Increasing the surface area of the solute by grinding it into smaller particles or increasing its contact area with the solvent can also speed up dissolution. Similarly, reducing the particle size of the solute can increase the rate of dissolution by providing more surface area for interaction with the solvent. Pressure, however, does not have a significant impact on the dissolution process and is not a factor that influences the rate at which a solute dissolves in a solvent.

4. Which of the following is directly transcribed from DNA and represents the first step in protein synthesis?

• A. siRNA
• B. rRNA
• C. mRNA
• D. tRNA

Correct answer: C

Rationale: mRNA (messenger RNA) is directly transcribed from DNA in the nucleus during the process of transcription. It serves as a template for protein synthesis during translation in the cytoplasm. mRNA carries genetic information from the DNA to the ribosomes, where it determines the sequence of amino acids in a protein. Thus, mRNA represents the first step in protein synthesis as it carries the code from the DNA to be translated into a protein. Choice A, siRNA (small interfering RNA), is involved in post-transcriptional gene silencing and does not play a role in protein synthesis. Choice B, rRNA (ribosomal RNA), is a component of the ribosome and plays a structural and functional role in protein synthesis but is not directly transcribed from DNA. Choice D, tRNA (transfer RNA), is responsible for bringing amino acids to the ribosome during protein synthesis but is not directly transcribed from DNA.

5. Which of the following correctly orders the route of a fetus during childbirth?

• A. Uterus, cervix, vagina
• B. Cervix, uterus, vagina
• C. Uterus, vas deferens, vagina
• D. Ovary, fallopian tube, uterus

Correct answer: A

Rationale: The correct route of a fetus during childbirth is from the uterus, through the cervix, and then out through the vagina. The contractions of the uterus help push the fetus through the cervix and out through the vaginal canal during childbirth. Choice B is incorrect as it reverses the order of the cervix and uterus. Choice C is incorrect as it includes the vas deferens, which is not part of the female reproductive system. Choice D is incorrect as it lists structures from the female reproductive system but in the wrong order for childbirth.

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