Nursing Elites

1. Which of the following is an example of a chemical change?

• A. Dissolving sugar in water
• B. Boiling water
• C. Rusting iron
• D. Crushing ice

Correct answer: C

Rationale: Rusting iron is an example of a chemical change because it involves a chemical reaction where iron reacts with oxygen in the presence of water to form iron oxide (rust). This reaction results in a change in the chemical composition of the iron, unlike dissolving sugar in water, boiling water, or crushing ice, which are physical changes. Dissolving sugar in water is a physical change as sugar molecules remain unchanged but disperse in water. Boiling water is also a physical change as water changes its state from liquid to gas due to heat. Crushing ice is a physical change as the solid ice changes its physical form without altering its chemical composition.

2. When human cells divide by meiosis, how many chromosomes do the resulting cells contain?

• A. 96
• B. 54
• C. 46
• D. 23

Correct answer: D

Rationale: When human cells divide by meiosis, the resulting cells contain 23 chromosomes. This is because meiosis is a cell division process that reduces the chromosome number by half, resulting in cells with a haploid number of chromosomes. In humans, the diploid number of chromosomes is 46. Therefore, after meiosis, the resulting cells have 23 chromosomes, ensuring the correct chromosome number is restored upon fertilization. Choices A, B, and C are incorrect as they do not represent the correct chromosome number resulting from meiosis in human cells.

3. What is the process by which genetic information is used to produce proteins?

• A. Replication
• B. Transcription
• C. Translation
• D. Mutation

Correct answer: C

Rationale: A) Replication is the process by which DNA is copied to produce an identical strand of DNA. This process occurs during cell division to ensure that each daughter cell receives a complete set of genetic information. B) Transcription is the process by which genetic information from DNA is copied into a complementary RNA molecule. This RNA molecule, known as messenger RNA (mRNA), serves as a template for protein synthesis during translation. C) Translation is the process by which the genetic information carried by mRNA is decoded to produce a specific sequence of amino acids, which are then assembled into a protein. This process occurs at the ribosomes in the cytoplasm of the cell. D) Mutation refers to a change in the DNA sequence that can result in alterations to the genetic information. Mutations can occur spontaneously or be induced by external factors such as radiation or chemicals. While mutations can impact protein synthesis, they are not the process by which genetic inf

4. In the context of optical fibers, chromatic dispersion refers to:

• A. The total internal reflection of light
• B. The spreading of light pulses due to different colors traveling at slightly different speeds
• C. The bending of light at the fiber core-cladding interface
• D. The absorption of light by the fiber material

Correct answer: B

Rationale: Chromatic dispersion in optical fibers refers to the spreading of light pulses due to different colors (wavelengths) traveling at slightly different speeds. This phenomenon can cause the different components of a light pulse to arrive at the receiver at slightly different times, leading to signal distortion. Choice A is incorrect because total internal reflection refers to the phenomenon where light is reflected back into the medium it originated from when hitting the boundary at an angle greater than the critical angle. Choice C is incorrect as it describes the principle of light being guided within an optical fiber through total internal reflection at the core-cladding interface. Choice D is incorrect as the absorption of light by the fiber material does not relate to chromatic dispersion.

5. What is the primary function of the respiratory system?

• A. to create sound and speech
• B. to take oxygen into the body while removing carbon dioxide
• C. to transport nutrients to the cells and tissue of the body
• D. to act as a barrier between the body’s organs and outside influences

Correct answer: B

Rationale: The primary function of the respiratory system is to take oxygen into the body through inhalation and remove carbon dioxide through exhalation. Oxygen is essential for cellular respiration and energy production, while carbon dioxide is a waste product that needs to be expelled from the body. This process is vital for the functioning of the body's cells and tissues. Choices A, C, and D are incorrect because sound and speech production, nutrient transport, and acting as a barrier against outside influences are not the primary functions of the respiratory system. While the respiratory system is involved in speech production to some extent, its primary role is in gas exchange for respiration.

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