Nursing Elites

1. Which of the following molecules acts as the genetic code's messenger?

• A. RNA
• B. Proteins
• C. DNA
• D. Carbohydrates

Correct answer: A

Rationale: The correct answer is RNA. RNA, particularly mRNA, serves as the messenger that carries genetic information from DNA to the ribosome, where proteins are synthesized. Proteins (choice B) are not the genetic code's messenger; they are synthesized based on the information carried by RNA. DNA (choice C) stores the genetic information but does not directly act as the messenger. Carbohydrates (choice D) are not involved in transmitting genetic information.

2. During which stage of mitosis does the nuclear envelope begin to disappear and the chromosomes start attaching to the spindle forming along the cell's axis?

• A. Prometaphase
• B. Metaphase
• C. Anaphase
• D. Prophase

Correct answer: A

Rationale: The correct answer is A, Prometaphase. During prometaphase, the nuclear envelope disintegrates, and chromosomes start attaching to spindle fibers. In metaphase, chromosomes align in the middle of the cell. Anaphase is characterized by the separation of sister chromatids, and prophase involves the condensation of chromosomes and the beginning of spindle formation.

3. In meiosis, the chromosome number is reduced from:

• A. 46 to 23
• B. 46 to 33
• C. 28 to 14
• D. 24 to 12

Correct answer: A

Rationale: The correct answer is A: "46 to 23." In meiosis, the chromosome number is reduced by half to form gametes for sexual reproduction. In humans, where the diploid chromosome number is 46, meiosis results in haploid cells with 23 chromosomes. Choices B, C, and D are incorrect because they do not represent the correct reduction in chromosome number during meiosis.

4. The cellular membrane contributes to all except which of the following?

• A. Cell energy production
• B. Cell permeability
• C. Cell communication
• D. Cell protection

Correct answer: A

Rationale: The cellular membrane is involved in regulating cell permeability, communication, and protection. However, it is not directly involved in energy production. Choice A is the correct answer because the cellular membrane does not produce energy; instead, it regulates the passage of molecules in and out of the cell. Choices B, C, and D are incorrect because the cell membrane plays key roles in controlling what enters and exits the cell, facilitating communication between cells, and providing structural support and protection to the cell.

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, which are responsible for protein synthesis. Ribosomes are the correct answer because they are the organelles directly associated with the rough endoplasmic reticulum. Microvilli (choice A), mitochondria (choice B), and lysosomes (choice C) are not typically located on the rough endoplasmic reticulum. Microvilli are found on the surface of cells to increase surface area, mitochondria are the powerhouses of the cell responsible for energy production, and lysosomes are membrane-bound organelles containing digestive enzymes.

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