Nursing Elites

1. What is the building block of DNA?

• A. Amino acid
• B. Nucleotide
• C. Phosphate group
• D. Fatty acid

Correct answer: B

Rationale: - Amino acids are the building blocks of proteins, not DNA. - Nucleotide is the correct building block of DNA. A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). - The option 'C) Phosphate group' is incorrect as it is only part of a nucleotide, not the complete building block of DNA. - Fatty acids are not the building blocks of DNA; they are a type of lipid molecule.

2. Which term refers to the resistance of a liquid to flow?

• A. Density
• B. Viscosity
• C. Surface tension
• D. Boiling point

Correct answer: B

Rationale: Viscosity is the term that refers to the resistance of a liquid to flow. It is a measure of how thick or sticky a fluid is and determines how easily a liquid can flow. Density (A) is a measure of how much mass is contained in a given volume and is not related to the resistance of a liquid to flow. Surface tension (C) is the property of a liquid that allows it to resist an external force due to the cohesive nature of its molecules, but it is not directly related to the resistance of a liquid to flow. Boiling point (D) is the temperature at which a liquid changes to a vapor and is not a measure of the resistance of a liquid to flow.

3. 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.

4. Which type of bond involves the complete transfer of electrons between atoms?

• A. Covalent bond
• B. Ionic bond
• C. Metallic bond
• D. Hydrogen bond

Correct answer: B

Rationale: The correct answer is B, Ionic bond. Ionic bond involves the complete transfer of electrons from one atom to another, resulting in the formation of cations and anions. This transfer leads to the creation of strong electrostatic attraction between the oppositely charged ions. Covalent bonds, on the other hand, involve the sharing of electrons between atoms to achieve stability. Metallic bonds are formed in metals, where a sea of delocalized electrons surrounds positively charged metal ions, contributing to the metal's properties. Hydrogen bonds are intermolecular forces that occur between a hydrogen atom and a highly electronegative atom like oxygen or nitrogen, not involving the complete transfer of electrons.

5. What is the protective fluid surrounding the brain and spinal cord called?

• A. Blood
• B. Cerebrospinal fluid
• C. Plasma
• D. Myelin

Correct answer: B

Rationale: Cerebrospinal fluid is the protective fluid that surrounds the brain and spinal cord. It acts as a cushion to protect these vital organs from injury and provides nutrients to the nervous system. Blood, plasma, and myelin are not the fluids specifically surrounding the brain and spinal cord. Blood is found within blood vessels, plasma is the liquid component of blood, and myelin is a fatty substance that forms a protective sheath around nerve fibers.

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