Nursing Elites

1. The term "barn" is a unit commonly used in nuclear physics to quantify:

• A. Energy (Electron volts are the standard unit for energy in nuclear physics)
• B. Radioactivity
• C. Nuclear cross-section
• D. Half-life

Correct answer: C

Rationale: The term 'barn' is a unit of measurement used in nuclear physics to quantify nuclear cross-section. Nuclear cross-section refers to the measure of the probability of a specific interaction occurring between particles during a nuclear reaction. The term 'barn' was coined based on its relation to the physical size of a nucleus, as it is a small unit of area used to describe the likelihood of a particle interacting with a nucleus. It is not used to quantify energy, radioactivity, or half-life, making options A, B, and D incorrect in this context.

2. What is the name of the sheath of connective tissue that surrounds a skeletal muscle?

• A. Epimysium
• B. Perimysium
• C. Endomysium
• D. Myofibril

Correct answer: A

Rationale: The correct answer is A: Epimysium. The epimysium is the outermost layer of connective tissue that surrounds a skeletal muscle. It provides protection and support to the muscle fibers within, as well as helps in transmitting forces generated by the muscle. Perimysium (B) is the connective tissue that surrounds bundles of muscle fibers called fascicles, while endomysium (C) is the connective tissue that surrounds individual muscle fibers. Myofibril (D) is a structure within muscle fibers that contains the contractile units responsible for muscle contraction. Therefore, in this context, the sheath of connective tissue surrounding a skeletal muscle is specifically referred to as the epimysium.

3. What is the building block of RNA?

• A. Amino acid
• B. Nucleotide
• C. Protein
• D. Fatty acid

Correct answer: B

Rationale: Rationale: A) Amino acid: Amino acids are the building blocks of proteins, not RNA. B) Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.

4. Antidiuretic hormone (ADH) helps the kidneys regulate:

• A. Acid-base balance
• B. Blood pressure
• C. Urine output by controlling water reabsorption
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Urine output by controlling water reabsorption.' Antidiuretic hormone (ADH) is released by the pituitary gland and acts on the kidneys to regulate water reabsorption. When ADH levels are high, the kidneys reabsorb more water, leading to concentrated urine and decreased urine output. This helps maintain the body's water balance and prevent dehydration. While ADH indirectly influences blood pressure by regulating blood volume, its primary function is to control water balance, not acid-base balance. Therefore, the correct answer is C.

5. What is the primary function of ribosomes in the cell?

• A. To synthesize lipids and other cellular components
• B. To package and transport proteins
• C. To break down macromolecules
• D. To translate mRNA into proteins

Correct answer: D

Rationale: Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C do not accurately describe the primary function of ribosomes in the cell.

6. What happens to the speed of a sound wave when it travels from air to water?

• A. It increases because water is denser.
• B. It decreases because water is denser.
• C. It remains the same.
• D. Speed depends on the frequency, not the medium.

Correct answer: A

Rationale: Sound waves travel faster in denser mediums like water compared to air due to stronger interactions between particles.

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