Nursing Elites

1. Where does gas exchange take place in the lungs?

• A. Bronchi
• B. Trachea
• C. Alveoli
• D. Pleura

Correct answer: C

Rationale: Gas exchange in the lungs occurs in the alveoli. Alveoli are tiny air sacs where oxygen from inhaled air diffuses into the bloodstream, and carbon dioxide from the blood diffuses into the alveoli to be exhaled. The bronchi are the main airways that branch off from the trachea, which is the windpipe connecting the larynx to the bronchi. The pleura is a membrane surrounding the lungs and lining the chest cavity, providing protection and lubrication for the lungs but not directly involved in gas exchange.

2. Which of the following is responsible for producing antibodies?

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Plasma

Correct answer: B

Rationale: White blood cells are responsible for producing antibodies. Antibodies are essential components of the immune system that help the body combat infections by identifying and neutralizing harmful pathogens. Red blood cells are primarily responsible for carrying oxygen, platelets are involved in blood clotting, and plasma is the liquid component of blood that carries nutrients and hormones.

3. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

• A. Centromere
• B. Chromatid
• C. Chromosome
• D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

4. What are the cellular functions of cilia and flagella?

• A. Cilia and flagella are responsible for cell movement.
• B. Cilia and flagella synthesize proteins.
• C. Cilia and flagella help protect the cell from its environment.
• D. Cilia and flagella have enzymes that help with digestion.

Correct answer: A

Rationale: Cilia and flagella are microtubule-based structures found on the surface of many eukaryotic cells. Their primary function is to facilitate cell movement. Cilia are short, numerous, and move in coordinated waving motions to move substances along the cell's surface. Flagella are longer and usually limited to one or a few per cell, providing a propeller-like movement for the cell. Both cilia and flagella aid in cell motility and are essential for various cellular functions, primarily involved in cell movement rather than protein synthesis, protection, or digestion. Therefore, choice A is correct as it accurately describes the primary function of cilia and flagella. Choices B, C, and D are incorrect as cilia and flagella are not involved in protein synthesis, cell protection, or digestion in cells.

5. Which of the following best describes the term homeostasis?

• A. The ability to maintain a constant body temperature
• B. The ability to maintain a stable internal environment
• C. The ability to increase body temperature when cold
• D. The ability to regulate blood glucose levels

Correct answer: B

Rationale: The correct answer is B, 'The ability to maintain a stable internal environment.' Homeostasis refers to the body's ability to regulate and maintain a stable internal environment, which includes variables like body temperature, pH levels, and fluid balance. It involves processes that help keep the body's internal conditions within a narrow range, despite external changes. While maintaining body temperature is a component of homeostasis, it is not the complete definition of the term. Choice C, 'The ability to increase body temperature when cold,' is incorrect as homeostasis aims to maintain stability rather than promoting temperature increases in response to external conditions. Choice D, 'The ability to regulate blood glucose levels,' is also incorrect as this is a specific function related to glucose homeostasis, which is a part of overall homeostatic processes but not the sole definition of homeostasis itself.

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