Nursing Elites

1. The tiny contractile units within muscle cells are called:

• A. Myocytes
• B. Myofibrils
• C. Sarcomeres
• D. Tendons

Correct answer: C

Rationale: The correct answer is C: Sarcomeres. Sarcomeres are the basic contractile units within muscle cells. They are made up of overlapping filaments of actin and myosin proteins, which slide past each other during muscle contraction, resulting in muscle movement. Myocytes (A) are muscle cells, myofibrils (B) are cylindrical structures within muscle fibers composed of sarcomeres, and tendons (D) are tough bands of connective tissue that connect muscle to bone. Therefore, sarcomeres are specifically responsible for muscle contraction within muscle cells.

2. In meiosis I, how are sister chromatids distinguished from homologous chromosomes?

• A. Sister chromatids share the same centromere, while homologues have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologues have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologues attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologues separate during anaphase II.

Correct answer: B

Rationale: While sister chromatids are identical copies of the same chromosome, homologous chromosomes are paired copies, each inherited from one parent. Crossing over during meiosis I can lead to slight differences in their DNA sequences.

3. 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 it determines how easily a liquid can flow. Density (A) is a measure of how much mass is contained in a given volume, 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, and boiling point (D) is the temperature at which a liquid changes to a vapor.

4. A decorative globe has a diameter of 25cm. What is its total surface area?

• A. 1570 sq cm
• B. 1963 sq cm
• C. 2513 sq cm
• D. 3142 sq cm

Correct answer: B

Rationale: Use the formula for surface area of a sphere: 4 * π * (radius)^2, where radius is half the diameter. Calculate the radius (12.5cm) and substitute: 4 * π * (12.5cm)^2 ≈ 1963 sq cm.

5. What is the medical term for ingrown hair?

• A. Folliculitis
• B. Hirsutism
• C. Pseudofolliculitis Barbae
• D. Alopecia

Correct answer: C

Rationale: The correct answer is C: 'Pseudofolliculitis Barbae.' This term specifically refers to ingrown hairs commonly seen in the beard area. Folliculitis (A) is inflammation of the hair follicles, not necessarily due to ingrown hairs. Hirsutism (B) is excessive hair growth, unrelated to ingrown hairs. Alopecia (D) is hair loss, which is also not related to ingrown hairs. Therefore, 'Pseudofolliculitis Barbae' is the medical term specifically used to describe ingrown hairs in the beard area, making it the correct answer.

6. What is the relationship between the Pauli exclusion principle and the structure of the atom?

• A. It defines the maximum number of electrons allowed in each energy level.
• B. It explains why oppositely charged particles attract each other.
• C. It describes the wave-particle duality of electrons.
• D. It determines the arrangement of protons and neutrons in the nucleus.

Correct answer: A

Rationale: It defines the maximum number of electrons allowed in each energy level. The Pauli exclusion principle states that no two electrons in an atom can occupy the same quantum state, which explains the specific sequence and structure of electron shells within the atom.

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