Nursing Elites

1. 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.

2. Which of the following enzymes is responsible for adding a nucleotide to a growing DNA chain?

• A. Helicase
• B. Ligase
• C. Nuclease
• D. Polymerase

Correct answer: D

Rationale: The correct answer is Polymerase. Polymerase is the enzyme responsible for adding nucleotides to a growing DNA chain during DNA replication. Helicase unwinds the DNA double helix to separate the DNA strands for replication, Ligase joins DNA fragments together by catalyzing the formation of phosphodiester bonds between them, and Nuclease cuts or degrades DNA strands. Therefore, choices A, B, and C are incorrect in the context of adding nucleotides to a growing DNA chain.

3. Which division of the autonomic nervous system is responsible for the 'rest and digest' response, promoting relaxation and conservation of energy?

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Somatic nervous system
• D. Central nervous system

Correct answer: B

Rationale: The correct answer is B: Parasympathetic nervous system. The parasympathetic nervous system is responsible for the 'rest and digest' response, promoting relaxation, conserving energy, and facilitating activities like digestion and lowering heart rate. The sympathetic nervous system, which is not the correct answer, triggers the 'fight or flight' response, preparing the body for stressful situations by increasing heart rate, dilating airways, and releasing adrenaline. The somatic nervous system (choice C) controls voluntary movements, not the autonomic functions related to 'rest and digest.' The central nervous system (choice D) includes the brain and spinal cord and is not specifically involved in the autonomic regulation of bodily functions like the 'rest and digest' response.

4. A satellite orbits the Earth at a constant speed. Which force is responsible for its circular motion?

• A. Gravitational force from the Earth
• B. Thrust from the satellite's engine
• C. Friction between the satellite and the atmosphere
• D. Normal force from the Earth's surface

Correct answer: A

Rationale: The gravitational force from the Earth is responsible for keeping the satellite in its circular orbit. This force provides the necessary centripetal force required to maintain the circular motion of the satellite. The gravitational force acts as the centripetal force, pulling the satellite towards the center of the Earth, thereby keeping it in its circular path. Choices B, C, and D do not provide the necessary force to keep the satellite in its circular path. Thrust from the satellite's engine would change the speed or direction of the satellite, not maintain its circular path. Friction between the satellite and the atmosphere would act as a resistive force, slowing down the satellite rather than maintaining its orbit. The normal force from the Earth's surface is perpendicular to the surface and does not contribute to the circular motion of the satellite. Therefore, the correct answer is A, as the gravitational force acts as the centripetal force to keep the satellite in its circular path around the Earth.

5. Differentiate between gene therapy and genetic engineering in the context of human intervention.

• A. Gene therapy aims to modify existing genes within body cells, while genetic engineering manipulates genes in embryos to be passed on to offspring.
• B. Gene therapy focuses on treating genetic diseases, while genetic engineering enhances desirable traits or eliminates undesirable ones.
• C. Both involve directly altering the DNA sequence, but gene therapy targets somatic cells and genetic engineering modifies germline cells.
• D. There is no fundamental difference; both terms are synonymous.

Correct answer: B

Rationale: A) Incorrect. Gene therapy does aim to modify existing genes within body cells, but genetic engineering does not necessarily manipulate genes in embryos to be passed on to offspring. Genetic engineering can involve modifying genes in any type of cell, not just embryos. B) Correct. Gene therapy is a medical intervention that aims to treat genetic diseases by correcting or replacing faulty genes within an individual's body cells. On the other hand, genetic engineering involves modifying genes to enhance specific traits or eliminate undesirable ones, often in the context of agriculture or biotechnology. C) Incorrect. While both gene therapy and genetic engineering involve altering DNA sequences, the distinction lies in the target cells. Gene therapy targets somatic cells (non-reproductive cells), while genetic engineering typically involves modifying germline cells (reproductive cells that can pass on genetic changes to offspring). D) Incorrect. There is

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