Nursing Elites

1. How do isotopes affect the atomic mass of an element?

• A. Isotopes have no effect on the atomic mass of an element.
• B. Isotopes cause the atomic mass of an element to vary slightly.
• C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
• D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: The atomic mass of an element is the average mass of all the isotopes of that element. Since isotopes have different numbers of neutrons, they also have slightly different masses. This variation in mass is what causes the atomic mass of an element to be a decimal number, rather than a whole number.

2. Which of the following best describes a chemical change?

• A. Melting ice to form water
• B. Dissolving sugar in water
• C. Burning wood to produce ash
• D. Crushing a can to reduce its size

Correct answer: c

Rationale: Chemical changes involve the formation of new substances with different chemical properties. Burning wood involves a chemical reaction where wood undergoes combustion, breaking down its chemical structure to produce new substances like ash and gases.

3. A car is traveling on a curved road. What force keeps the car moving along the curved path?

• A. Gravitational force
• B. Normal force from the road
• C. Air resistance
• D. Friction between the tires and the road

Correct answer: D

Rationale: In this case, static friction acts between the tires and the road, providing the centripetal force required to keep the car moving in a circle even though it's traveling in a straight line relative to the ground.

4. What is the role of transfer RNA (tRNA) in protein synthesis?

• A. Transcribes DNA into mRNA
• B. Decodes the genetic code on mRNA
• C. Carries specific amino acids to the ribosomes bas(a) Carries amino acids to the ribosomes: This is the function of transfer RNA (tRNA), not ribosomal RNA. (b) Reads the genetic code on mRNA: This is the function of the ribosomes as a whole, not just the ribosomal RNA. (d) Controls the rate of protein synthesis: This is a more complex process involving various factors, not solely ribosomal RNA. ? ed on the mRNA
• D. Modifies the structure of proteins

Correct answer: C

Rationale: Rationale: A) Transcribes DNA into mRNA: This is the function of RNA polymerase, not transfer RNA (tRNA). tRNA is involved in protein synthesis, not transcription. B) Decodes the genetic code on mRNA: This is the function of tRNA during translation. tRNA molecules carry specific amino acids and recognize the codons on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. C) Carries specific amino acids to the ribosomes: This is the primary role of tRNA in protein synthesis. Each tRNA molecule is specific for a particular amino acid and carries it to the ribosome, where it is added to the growing protein chain. D) Modifies the structure of proteins: This is not a function of tRNA. Protein modification can occur after translation is complete and involves other cellular processes and molecules.

5. Which vitamin is essential for proper absorption of calcium and plays a role in lung function?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: The correct answer is C, Vitamin D. Vitamin D is essential for the proper absorption of calcium in the intestines, which is crucial for maintaining strong bones and teeth. Additionally, Vitamin D plays a role in lung function by supporting respiratory health and reducing inflammation in the lungs. Vitamin A is important for vision and immune function, Vitamin B12 is necessary for red blood cell formation and neurological function, and Vitamin E is an antioxidant that helps protect cells from damage.

6. What is the name of a condition where the immune system mistakenly attacks healthy body tissues?

• A. Allergy
• B. Autoimmune disease
• C. Immunodeficiency
• D. Sepsis

Correct answer: B

Rationale: The correct answer is B: Autoimmune disease. This condition occurs when the immune system mistakenly targets and attacks healthy tissues in the body, leading to inflammation and tissue damage. Autoimmune diseases can affect various organs and systems in the body, such as rheumatoid arthritis, lupus, and multiple sclerosis. Allergies (A) involve the immune system overreacting to harmless substances, but they do not involve attacking healthy tissues. Immunodeficiency (C) refers to a weakened immune system that is less able to fight off infections. Sepsis (D) is a life-threatening condition caused by the body's response to an infection, not an autoimmune reaction.

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