Nursing Elites

1. Newton's rings are a visual demonstration of:

• A. Diffraction
• B. Doppler effect
• C. Polarization
• D. Thin-film interference

Correct answer: D

Rationale: Newton's rings are a series of concentric colored rings observed when light is reflected between a spherical surface and a flat surface. This phenomenon is a result of thin-film interference, which occurs due to the varying thickness of the air gap between the surfaces. The interference of light waves results in constructive and destructive interference, leading to the formation of the rings. Diffraction, the bending of light around obstacles, is not the cause of Newton's rings. The Doppler effect involves the change in frequency of waves due to motion and is not relevant in this context. Polarization refers to the orientation of electromagnetic waves, which is not the primary factor in the formation of Newton's rings. Therefore, the correct answer is D: Thin-film interference.

2. What property of a wave determines the loudness of sound when heard by the human ear?

• A. Frequency
• B. Amplitude
• C. Wavelength
• D. Velocity

Correct answer: b

Rationale: The amplitude of a sound wave correlates with its perceived loudness by the human ear.

3. 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.

4. What is the process by which bacteria can acquire new genetic material from their environment?

• A. Transformation
• B. Transduction
• C. Conjugation
• D. All of the above

Correct answer: D

Rationale: Rationale: A) Transformation: Transformation is the process by which bacteria can take up free DNA from their environment and incorporate it into their own genome. This can lead to the acquisition of new genetic material and traits. B) Transduction: Transduction is a process where genetic material is transferred from one bacterium to another by a bacteriophage (a virus that infects bacteria). During transduction, the bacteriophage carries bacterial DNA from one host cell to another, allowing for the transfer of genetic material. C) Conjugation: Conjugation is a mechanism of horizontal gene transfer in bacteria where genetic material is transferred between two bacterial cells that are in direct contact. This transfer is mediated by a conjugative plasmid that carries the genetic information to be transferred. Therefore, all of the processes mentioned (transformation, transduction, and conjugation) are ways in which bacteria can acquire new genetic material from their environment.

5. Which word is most closely associated with the adjective "ambiguous"?

• A. Precise
• B. Vague
• C. Definite
• D. Straightforward

Correct answer: B

Rationale: "Ambiguous" implies uncertainty or multiple interpretations, making "vague" its closest synonym.

6. What is the difference between homologous chromosomes and sister chromatids?

• A. Homologous chromosomes have the same genes but may have different alleles, while sister chromatids are identical copies of the same chromosome.
• B. Homologous chromosomes are only found in diploid cells, while sister chromatids are found in both haploid and diploid cells.
• C. Both homologous chromosomes and sister chromatids are genetically identical, but only sister chromatids separate during mitosis.
• D. Both homologous chromosomes and sister chromatids can separate during mitosis, but only homologous chromosomes have different alleles.

Correct answer: A

Rationale: Rationale: - Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene). - Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle. - During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.

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