Nursing Elites

1. What is the primary function of the endocrine system?

• A. To fight infection
• B. To transport oxygen
• C. To regulate body functions through hormones
• D. To break down food

Correct answer: C

Rationale: The correct answer is C: 'To regulate body functions through hormones.' The endocrine system is responsible for producing and secreting hormones that help regulate various body functions such as growth, metabolism, reproduction, and mood. It does not primarily function to fight infection (A), transport oxygen (B), or break down food (D). While the immune system fights infection, the respiratory system transports oxygen, and the digestive system breaks down food, the main role of the endocrine system is to maintain homeostasis by coordinating and controlling bodily functions through the release of hormones.

2. What happens when the diaphragm contracts?

• A. Air is expelled from the lungs.
• B. The lungs expand to allow air intake.
• C. The vocal cords vibrate to produce sound.
• D. The trachea narrows to control airflow.

Correct answer: B

Rationale: When the diaphragm contracts, it moves downward, creating more space in the chest cavity. This expansion of the chest cavity causes the lungs to expand as well, allowing air to be drawn into the lungs during inhalation. Therefore, the correct answer is that the lungs expand to allow air intake when the diaphragm contracts. Choices A, C, and D are incorrect because when the diaphragm contracts, it does not expel air from the lungs, cause the vocal cords to vibrate, or narrow the trachea to control airflow.

3. Which of the following nucleic acids carries amino acids to organelles called ribosomes, where the amino acids are linked one by one to produce a polypeptide?

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

Correct answer: D

Rationale: tRNA is the correct answer as it carries amino acids to the ribosomes during protein synthesis. Transfer RNA (tRNA) plays a crucial role in protein synthesis by bringing specific amino acids to the ribosome according to the mRNA sequence. Once at the ribosome, the amino acids are linked together to form a polypeptide chain. This process is essential for the creation of proteins in the cell, highlighting the significance of tRNA in the translation process. Choice A, DNA, is incorrect as DNA does not directly participate in protein synthesis. Choice B, mRNA, is incorrect as mRNA carries the genetic information from DNA to the ribosome but does not directly carry amino acids. Choice C, rRNA, is incorrect as ribosomal RNA is a component of the ribosome structure and is involved in protein synthesis but does not carry amino acids like tRNA.

4. Which of the following is NOT a characteristic of living organisms?

• A. Made up of cells
• B. Able to reproduce
• C. Require energy
• D. Non-motile

Correct answer: D

Rationale: A) Made up of cells: All living organisms are composed of one or more cells, a fundamental characteristic of life as defined by cell theory. B) Able to reproduce: Reproduction is a key characteristic of living organisms to pass on genetic information. C) Require energy: Energy is essential for carrying out life processes like growth and maintenance of homeostasis. D) Non-motile: While some living organisms are non-motile, movement is common in many organisms for survival activities like finding food, escaping predators, and responding to the environment. Therefore, being non-motile is not a universal characteristic of living organisms, making it the correct answer in this context.

5. What is the function of ribosomal RNA (rRNA)?

• A. Carries amino acids to the ribosomes
• B. Reads the genetic code on mRNA
• C. Forms the structural framework of ribosomes
• D. Controls the rate of protein synthesis

Correct answer: C

Rationale: Ribosomal RNA (rRNA) plays a crucial role in forming the structural framework of ribosomes. Ribosomes are the cellular organelles responsible for protein synthesis and consist of both protein and rRNA components. The primary function of rRNA is to provide the structural support necessary for ribosomes to function properly. This structural framework allows the ribosome to interact with messenger RNA (mRNA) and transfer RNA (tRNA) during translation, where genetic information encoded in mRNA is used to assemble proteins from amino acids. Therefore, rRNA's main role is in contributing to the structure and function of ribosomes, rather than directly carrying amino acids, reading the genetic code, or controlling the rate of protein synthesis. Choices A, B, and D are incorrect because rRNA does not carry amino acids to the ribosomes (tRNA does this), read the genetic code (this is the role of ribosomes and tRNA), or control the rate of protein synthesis (this is regulated by various factors but not directly by rRNA).

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