Nursing Elites

1. What information can be obtained from the mass number of an element?

• A. The number of protons in the nucleus
• B. The total number of protons and neutrons
• C. The number of electrons in the valence shell
• D. The element's chemical reactivity

Correct answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in the nucleus. This information is crucial for determining the atomic mass of the element and understanding its stability and isotopes. The number of protons in the nucleus (option A) is represented by the atomic number, not the mass number. The number of electrons in the valence shell (option C) is related to the element's position in the periodic table and its chemical properties, but it is not directly determined by the mass number. The element's chemical reactivity (option D) is influenced by the number and arrangement of electrons in the atom's energy levels, not by the mass number.

2. Electroencephalography (EEG) measures electrical activity in the brain, primarily reflecting the activity of:

• A. Neurons
• B. Astrocytes
• C. Oligodendrocytes
• D. Microglia

Correct answer: A

Rationale: EEG measures electrical activity in the brain, primarily reflecting the activity of neurons. Neurons are the primary cells responsible for generating electrical impulses and transmitting information in the brain. Astrocytes, oligodendrocytes, and microglia are other types of cells in the brain that have different functions and are not primarily involved in generating the electrical activity measured by EEG. Astrocytes support neuronal function, oligodendrocytes produce myelin to insulate axons, and microglia are involved in immune responses and maintaining brain health, but they do not generate the electrical impulses detected by EEG.

3. What is the difference between a germline mutation and a somatic mutation?

• A. Germline mutations are passed to offspring, while somatic mutations are not.
• B. Germline mutations occur in reproductive cells, while somatic mutations occur in body cells.
• C. Germline mutations only affect genes, while somatic mutations can affect any DNA.
• D. Germline mutations are always beneficial, while somatic mutations are always harmful.

Correct answer: B

Rationale: Rationale: - Germline mutations are changes in the DNA of reproductive cells (sperm or egg cells) and can be passed on to offspring, affecting all cells in the resulting organism. - Somatic mutations are changes in the DNA of non-reproductive cells (body cells) and are not passed on to offspring. These mutations only affect the cells that arise from the mutated cell. - Option A is incorrect because somatic mutations are not passed to offspring. - Option C is incorrect because both germline and somatic mutations can affect any DNA. - Option D is incorrect because the effects of mutations, whether germline or somatic, can be beneficial, harmful, or have no significant impact.

4. Which of the following is a strong base commonly used in cleaning products?

• A. Sodium hydroxide (NaOH)
• B. Ammonium hydroxide (NH₄OH)
• C. Calcium hydroxide (Ca(OH)₂)
• D. Potassium hydroxide (KOH)

Correct answer: A

Rationale: Sodium hydroxide (NaOH) is a strong base commonly used in cleaning products due to its effectiveness in breaking down grease and fats. It is known for its corrosive properties and is commonly found in drain cleaners and oven cleaners. While ammonium hydroxide, calcium hydroxide, and potassium hydroxide are also bases, they are not as strong as sodium hydroxide and are not as commonly used in cleaning products. Ammonium hydroxide is more commonly found in household cleaning products for its disinfectant properties, calcium hydroxide is used in agriculture and construction, and potassium hydroxide is often used in industries like soap manufacturing and biodiesel production.

5. Which of the following nucleic acids carries the genetic information copied from DNA to the ribosomes?

• A. DNA
• B. mRNA
• C. rRNA
• D. tRNA

Correct answer: B

Rationale: The correct answer is B: mRNA. Messenger RNA (mRNA) is responsible for carrying the genetic information copied from DNA to the ribosomes for protein synthesis. mRNA serves as a temporary copy of the genetic instructions stored in DNA and acts as a messenger between the nucleus and ribosomes in the cytoplasm where protein synthesis occurs. While rRNA (ribosomal RNA) and tRNA (transfer RNA) play essential roles in the process of translation at the ribosomes, mRNA is the nucleic acid directly involved in carrying the genetic code for protein synthesis. Therefore, choices A, C, and D are incorrect as DNA is the original genetic material, rRNA is a component of the ribosomes, and tRNA carries amino acids during protein synthesis, respectively.

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