Nursing Elites

1. Which part of the heart is responsible for generating the QRS complex on an ECG?

• A. Sinoatrial node (SA node)
• B. Atrioventricular node (AV node)
• C. Bundle of His
• D. Ventricular muscle cells

Correct answer: D

Rationale: The QRS complex on an ECG represents ventricular depolarization. This electrical activity is generated by the ventricular muscle cells. While the SA node generates the P wave, the AV node delays the impulse, and the Bundle of His and Purkinje fibers assist in rapidly conducting the impulse through the ventricles, it is the ventricular muscle cells that specifically create the QRS complex. Therefore, choice D, Ventricular muscle cells, is the correct answer. Choices A, B, and C are incorrect as they are primarily involved in initiating and coordinating the electrical impulses in the heart but do not directly generate the QRS complex on an ECG.

2. What is the role of DNA in heredity?

• A. Provides energy for the cell
• B. Determines the structure and function of proteins
• C. Stores and transmits genetic information
• D. Controls cell division

Correct answer: C

Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA's primary role is to store and transmit genetic information, making option C the correct answer. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

3. Which structure in the heart is responsible for pumping oxygenated blood to the body?

• A. Right ventricle
• B. Left ventricle
• C. Left atrium
• D. Right atrium

Correct answer: B

Rationale: The left ventricle is the chamber responsible for pumping oxygenated blood from the heart to the body. It receives oxygen-rich blood from the left atrium and contracts to push this blood out to the rest of the body through the aorta. The right ventricle pumps deoxygenated blood to the lungs for oxygenation, making choices A, C, and D incorrect for this function. Therefore, the correct answer is B, the Left ventricle.

4. Where does fertilization of the egg by sperm typically occur?

• A. Ovary
• B. Fallopian tube
• C. Uterus
• D. Vagina

Correct answer: B

Rationale: Fertilization of the egg by sperm typically occurs in the fallopian tube. After ovulation, the egg is released from the ovary and travels through the fallopian tube, where it may encounter sperm for fertilization. The fallopian tube provides the ideal environment, including necessary nutrients and conditions, for fertilization to take place before the fertilized egg moves towards the uterus for implantation. Choices A, C, and D are incorrect because fertilization does not occur in the ovary, uterus, or vagina. The ovary releases the egg, the uterus is the site for implantation, and the vagina is part of the birth canal but not the typical site for fertilization.

5. Lymph nodes, found along lymphatic vessels, are important for:

• A. Storing blood
• B. Producing antibodies
• C. Filtering lymph and trapping harmful substances
• D. All of the above

Correct answer: C

Rationale: Lymph nodes are essential for filtering lymph and trapping harmful substances. They are a vital part of the immune system as they remove pathogens and harmful substances from the lymph before it returns to the bloodstream. Lymph nodes do not store blood or produce antibodies, making choice C the correct answer. Choice A is incorrect because lymph nodes do not store blood; they primarily filter lymph. Choice B is incorrect as lymph nodes do not produce antibodies; that function is mainly carried out by specialized cells within the immune system. Choice D is incorrect as lymph nodes do not perform all the functions listed, making it an incorrect answer.

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