Nursing Elites

1. What is the primary function of the cell membrane?

• 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 genetic material

Correct answer: B

Rationale: The primary function of the cell membrane, also known as the plasma membrane, is to regulate the movement of substances in and out of the cell. It acts as a selectively permeable barrier, allowing specific molecules to pass through while blocking others. This role is crucial for maintaining the internal environment of the cell by enabling essential nutrients to enter and waste products to exit. While the cell membrane provides some structural support for the cell, its main function is substance transport. Protein and lipid synthesis predominantly occur in organelles like the endoplasmic reticulum and Golgi apparatus, and storing genetic material is the nucleus's responsibility. Therefore, choices C (To synthesize proteins and lipids) and D (To store genetic material) are incorrect as these functions are carried out by other cell organelles, not the cell membrane.

2. The pH scale is used to indicate the concentration of:

• A. Hydrogen ions
• B. Oxygen
• C. Salts
• D. Sugar molecules

Correct answer: A

Rationale: The pH scale is a measure of the concentration of hydrogen ions in a solution, representing its acidity or basicity. A lower pH value indicates higher hydrogen ion concentration and acidity, while a higher pH value indicates lower hydrogen ion concentration and basicity. Choice A, 'Hydrogen ions,' is the correct answer because the pH scale specifically measures the concentration of hydrogen ions in a solution. Choices B, C, and D are incorrect as the pH scale is not used to indicate the concentration of oxygen, salts, or sugar molecules.

3. Which organ stores and concentrates bile?

• A. Liver
• B. Gallbladder
• C. Pancreas
• D. Stomach

Correct answer: B

Rationale: The correct answer is B: Gallbladder. The gallbladder is the organ that stores and concentrates bile produced by the liver. Bile is essential for the digestion of fats in the small intestine. The liver produces bile, which is then stored and concentrated in the gallbladder until it is released into the small intestine when needed. Choices A, C, and D are incorrect because the liver produces bile, the pancreas produces digestive enzymes, and the stomach is primarily involved in the digestion of food through acid secretion and mechanical processes, not in storing bile.

4. Which structure in the eye is responsible for detecting light?

• A. Cornea
• B. Retina
• C. Lens
• D. Iris

Correct answer: B

Rationale: The retina is the correct answer as it is the light-sensitive structure in the eye that detects light and converts it into signals for the brain to process visual information. The cornea is the transparent outer covering of the eye that helps to focus incoming light onto the lens. The lens further focuses the light onto the retina, which is where the actual light detection and signal conversion occur. The iris, on the other hand, controls the amount of light entering the eye by adjusting the size of the pupil but is not directly responsible for detecting light.

5. From which of the following germ layers does the nervous system develop?

• A. Ectoderm
• B. Endoderm
• C. Gastroderm
• D. Mesoderm

Correct answer: A

Rationale: The correct answer is A: Ectoderm. The nervous system develops from the ectoderm, which is the outermost of the three germ layers. The ectoderm gives rise to structures such as the skin, hair, nails, and the entire nervous system. Choices B, C, and D are incorrect because the endoderm gives rise to the lining of the gut and associated organs, the gastroderm is not a recognized germ layer, and the mesoderm forms structures like muscles, bones, blood, and the circulatory system, but not the nervous system.

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