Nursing Elites

1. What is the diastole cycle in the heart?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Pulse rate of the heart
• D. Blood circulation

Correct answer: A

Rationale: The diastole cycle in the heart refers to the relaxation phase, where the heart chambers relax and fill with blood. This phase is crucial for the heart to refill and prepare for the next contraction (systole), which pumps blood out of the heart. Therefore, the correct answer is choice A, 'Relaxation of the heart.' Choices B, C, and D are incorrect in the context of cardiac physiology. Choice B, 'Contraction of the heart,' refers to systole, the phase of heart contraction. Choice C, 'Pulse rate of the heart,' is related to the number of heartbeats per minute, not the diastole cycle specifically. Choice D, 'Blood circulation,' is a broader term that encompasses the entire circulatory system rather than focusing on the heart's specific relaxation phase.

2. When water boils, it changes from a liquid to a gas. This is an example of a:

• A. Chemical reaction
• B. Physical change
• C. Nuclear reaction
• D. Biological process

Correct answer: B

Rationale: This is a physical change because boiling water involves a change in state from liquid to gas without altering the chemical composition of the water molecules. In a chemical reaction, new substances are formed by breaking and forming chemical bonds, which is not the case during boiling. A nuclear reaction involves changes in atomic nuclei, which are not occurring during boiling. A biological process refers to activities related to living organisms, which is not applicable to the change from liquid to gas in boiling water.

3. Which of the following organs is responsible for the mechanical breakdown of food into smaller pieces?

• A. Esophagus
• B. Stomach
• C. Small intestine
• D. Mouth

Correct answer: D

Rationale: The correct answer is D: Mouth. The mouth is responsible for the mechanical breakdown of food through chewing and mixing with saliva. This process is essential for breaking down food into smaller, more digestible pieces before swallowing. The esophagus (choice A) is a muscular tube that transports food from the mouth to the stomach and does not participate in the mechanical breakdown of food. The stomach (choice B) primarily functions to further break down food using acids and enzymes, rather than mechanical means. The small intestine (choice C) is responsible for absorbing nutrients from the digested food, not for the mechanical breakdown of food.

4. Balance the chemical equation: C4H10 + O2 → CO2 + H2O. What is the coefficient for oxygen?

• A. 5
• B. 6
• C. 7
• D. 8

Correct answer: B

Rationale: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In this case, there are 10 oxygen atoms on the right side (5 in CO2 and 5 in H2O). To balance this, we need to add a coefficient of 6 in front of O2 on the left side, resulting in 6 O2 molecules. This change will give us a total of 12 oxygen atoms on both sides, making the equation balanced. Choice A (5) is incorrect because it does not account for all the oxygen atoms present in the products. Choices C (7) and D (8) are incorrect as they would result in an imbalance in the number of oxygen atoms on both sides of the equation.

5. How do organisms maintain homeostasis?

• A. By increasing their body temperature, blood pH, and fluid balance.
• B. By undergoing biochemical processes and absorbing energy to increase entropy.
• C. By undergoing biochemical processes to maintain the order of their external environment.
• D. By using free energy and matter via biochemical processes to work against entropy.

Correct answer: D

Rationale: Organisms maintain homeostasis by utilizing free energy and matter through biochemical processes to counteract entropy, which helps in preserving internal stability. This process involves maintaining a balance within the organism's internal environment despite external changes, ensuring proper functioning and survival. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance alone do not define the comprehensive process of maintaining homeostasis. Choice B is incorrect as absorbing energy to increase entropy goes against the concept of maintaining internal stability. Choice C is incorrect as maintaining the order of the external environment does not directly contribute to the organism's internal stability and balance.

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