Nursing Elites

1. What is the main function of vacuoles in plant cells?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store water, enzymes, and waste products

Correct answer: D

Rationale: Vacuoles in plant cells primarily function as storage organelles. They store water, enzymes, pigments, and waste products, helping to maintain turgor pressure within the cell. This turgor pressure provides structural support for the plant cell. While vacuoles can also participate in transporting substances within the cell, their main role is storage. The synthesis of proteins and lipids is mainly handled by other organelles such as the endoplasmic reticulum and Golgi apparatus. Choice A is incorrect because while vacuoles indirectly contribute to structural support by maintaining turgor pressure, their primary function is storage. Choice B is incorrect as vacuoles are not primarily responsible for transporting substances in and out of the cell. Choice C is incorrect as vacuoles do not synthesize proteins and lipids; this function is carried out by other organelles.

2. The shimmering image of water seen on a hot road is a well-known example of:

• A. Reflection
• B. Refraction
• C. Interference
• D. Polarization

Correct answer: B

Rationale: The shimmering image of water seen on a hot road is a result of refraction, not reflection. Refraction is the bending of light as it passes from one medium to another of different optical density. In this case, the hot air just above the road has a different density than the cooler air above it, causing light to bend and create the illusion of water on the road. Refraction is the most suitable explanation for this phenomenon, as it involves the bending of light rays due to the change in the medium's optical density, producing the visual effect observed on the hot road. Reflection, interference, and polarization do not involve the bending of light due to changes in optical density and are not applicable to the scenario described on the hot road.

3. Which term refers to the relaxation of the heart muscle?

• A. Diastole
• B. Systole
• C. Asystole
• D. Cardiastole

Correct answer: A

Rationale: The correct answer is A: Diastole. Diastole is the phase of the heartbeat when the heart muscle relaxes, allowing the chambers to fill with blood. Systole, on the other hand, refers to the contraction phase of the heart when it pumps blood out. Asystole is the absence of heart contractions, often referred to as cardiac arrest. Cardiastole is not a recognized medical term in relation to heart muscle relaxation, making it an incorrect choice.

4. Which type of white blood cell directly attacks and destroys pathogens like bacteria and viruses?

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Eosinophils

Correct answer: A

Rationale: Neutrophils are a type of white blood cell that plays a crucial role in the immune system's response to infections. They are phagocytes, meaning they engulf and destroy pathogens like bacteria and viruses. Neutrophils are the most abundant type of white blood cell and are known for their rapid response to infections, making them the primary cell type that directly attacks and destroys pathogens. Lymphocytes, although important in adaptive immunity, are not primarily responsible for directly attacking and destroying pathogens. Monocytes are involved in phagocytosis and immune response regulation but are not the primary cell type for direct pathogen destruction like neutrophils. Eosinophils are mainly involved in combating multicellular parasites and are not the primary cell type for targeting bacteria and viruses.

5. Which of the following conditions is characterized by a high percentage of CO2 and a very low percentage of O2 in the blood?

• A. Asphyxia
• B. Emphysema
• C. Eupnea
• D. Hypoxia

Correct answer: A

Rationale: Asphyxia is the correct answer as it refers to a condition with high CO2 and low O2 levels in the blood. Asphyxia can result in oxygen deprivation and excess carbon dioxide in the bloodstream, posing a life-threatening situation if not treated promptly. Emphysema is a chronic lung disease characterized by the damage to the air sacs in the lungs, leading to breathing difficulties. Eupnea denotes normal breathing without any abnormalities. Hypoxia, on the other hand, involves low oxygen levels reaching the body's tissues, which can result from various causes such as reduced oxygen in the air or respiratory issues.

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