Nursing Elites

1. What is the function of introns in eukaryotic genes?

• A. They code for protein sequences.
• B. They are involved in gene regulation.
• C. They are removed during mRNA processing.
• D. They are non-functional remnants of ancient DNA.

Correct answer: C

Rationale: A) Introns do not code for protein sequences. Exons are the segments of DNA that code for proteins. B) While introns can indirectly influence gene regulation, their primary function is not directly involved in gene regulation. C) Introns are non-coding regions of DNA that are transcribed into pre-mRNA but are removed during mRNA processing through a process called splicing. This allows only the exons to be included in the mature mRNA that will be translated into proteins. D) While introns were once thought to be non-functional remnants of ancient DNA, research has shown that they can have regulatory functions and play a role in gene expression.

2. Which of the following substances is an example of an acidic gas?

• A. Nitrogen (N₂)
• B. Carbon dioxide (CO₂)
• C. Sulfur dioxide (SO₂)
• D. Oxygen (O₂)

Correct answer: C

Rationale: The correct answer is C, Sulfur dioxide (SO₂). Sulfur dioxide is an acidic gas because when dissolved in water, it forms sulfurous acid, which imparts acidic properties. Nitrogen (N₂), carbon dioxide (CO₂), and oxygen (O₂) are not considered acidic gases. Nitrogen is a neutral gas, carbon dioxide forms a weakly acidic solution when dissolved in water, and oxygen is a neutral gas.

3. After water absorption in the large intestine, what waste product remains and is eventually eliminated from the body?

• A. Chyme
• B. Bolus
• C. Glucose
• D. Feces

Correct answer: D

Rationale: The correct answer is D: Feces. After the large intestine absorbs water and electrolytes from digested food material, the waste product that remains is feces. Feces consist of undigested food material, bacteria, and waste products that were not absorbed by the body. Choice A, Chyme, is incorrect as chyme is a semi-fluid mass of partially digested food that moves from the stomach to the small intestine. Choice B, Bolus, is incorrect as bolus refers to a rounded mass of food that is swallowed. Choice C, Glucose, is incorrect as glucose is a simple sugar that serves as a vital energy source for the body and is not a waste product in this context.

4. Which of the following is an example of a fibrous protein?

• A. Insulin
• B. Keratin
• C. Hemoglobin
• D. Collagen

Correct answer: D

Rationale: A) Insulin is a hormone, not a fibrous protein. It is produced in the pancreas and regulates blood sugar levels. B) Keratin is a fibrous structural protein found in hair, nails, and the outer skin layer, providing strength and protection. C) Hemoglobin is a globular protein in red blood cells responsible for oxygen transport; it is not fibrous. D) Collagen is a fibrous protein found in tendons, ligaments, and skin, offering strength and structure to connective tissues. Therefore, the correct answer is collagen, making it the main component of various connective tissues.

5. Where does the electron transport chain occur in the cell?

• A. Cytosol
• B. Golgi apparatus
• C. Inner mitochondrial membrane
• D. Nucleus

Correct answer: C

Rationale: The electron transport chain occurs in the inner mitochondrial membrane. This process is crucial for the generation of ATP, the cell's energy currency. Choice A (Cytosol) is incorrect as the electron transport chain does not take place in the cytosol. Choice B (Golgi apparatus) is also incorrect as the Golgi apparatus is involved in modifying, sorting, and packaging of proteins. Choice D (Nucleus) is incorrect as the nucleus houses the cell's genetic material but is not the location of the electron transport chain.

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