Nursing Elites

1. Which of the following is a lipid that is a membrane component and a precursor to significant hormones?

• A. Nucleic acids
• B. Proteins
• C. Carbohydrates
• D. Steroids

Correct answer: D

Rationale: The correct answer is D, Steroids. Steroids are a type of lipid that function as essential components of cell membranes and serve as precursors for significant hormones like estrogen and testosterone. Nucleic acids (choice A) are not lipids but are molecules like DNA and RNA that store genetic information. Proteins (choice B) and carbohydrates (choice C) are biomolecules but are not lipids and do not serve as precursors for hormones or membrane components.

2. What is the most important function of carbohydrates?

• A. Store and provide energy for the body
• B. Create amino acids
• C. Maintain body temperature
• D. Insulate body organs against shock

Correct answer: A

Rationale: The most important function of carbohydrates is to store and provide energy for the body through metabolic processes. Carbohydrates are broken down into glucose, which is used as the primary source of energy for various cellular functions. Choice B is incorrect because amino acids are the building blocks of proteins, not directly created by carbohydrates. Choice C is incorrect as the regulation of body temperature is primarily controlled by mechanisms such as sweating and shivering, not carbohydrates. Choice D is incorrect as insulation of body organs against shock is mainly provided by adipose tissue, not carbohydrates.

3. What is the composition of the cellular membrane?

• A. A bilayer of phospholipid molecules
• B. A single layer of phospholipid molecules
• C. Proteins that act as transport highways
• D. Carbohydrates

Correct answer: A

Rationale: The cellular membrane is primarily composed of a phospholipid bilayer, which consists of two layers of phospholipid molecules. These molecules have a hydrophilic (water-attracting) head and hydrophobic (water-repelling) tail, creating a barrier that separates the internal cellular environment from the external surroundings. While proteins are embedded within this bilayer and act as transport channels, receptors, and structural support, carbohydrates are found on the outer surface of the membrane for cell recognition and signaling purposes. Therefore, the correct answer is a bilayer of phospholipid molecules.

4. Which of the following is the process that reduces cells originally classified as diploid to haploid?

• A. Meiosis
• B. Photosynthesis
• C. Mitosis
• D. Cytokinesis

Correct answer: A

Rationale: The correct answer is A, Meiosis. Meiosis is the cell division process that reduces the chromosome number from diploid to haploid, which is essential for sexual reproduction. Choice B, Photosynthesis, is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Choice C, Mitosis, is a cell division process that results in two diploid daughter cells with the same number of chromosomes as the parent cell. Choice D, Cytokinesis, is the division of the cytoplasm following cell division.

5. What is located on the rough endoplasmic reticulum?

• A. Microvilli
• B. Mitochondria
• C. Lysosomes
• D. Ribosomes

Correct answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, not microvilli, mitochondria, or lysosomes. Ribosomes are responsible for protein synthesis, making them an essential component of the rough endoplasmic reticulum.

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