Nursing Elites

1. Antigenic variation, a common strategy used by some viruses, allows them to:

• A. Produce toxins
• B. Evade the immune system
• C. Survive outside a host
• D. Replicate rapidly

Correct answer: B

Rationale: Antigenic variation is a strategy used by some viruses to evade the host's immune response. By constantly changing their surface antigens, viruses can avoid recognition and destruction by the immune system. This allows the virus to persist in the host and continue replicating, leading to prolonged infection and potential transmission to other hosts. Antigenic variation does not directly involve the production of toxins, survival outside a host, or rapid replication, making options A, C, and D incorrect in this context.

2. Where is the ball-and-socket joint, allowing a wide range of motion, found?

• A. Upper arm (humerus) and shoulder blade (scapula)
• B. Collarbone (clavicle) and breastbone (sternum)
• C. Two vertebrae in the spine
• D. Ribs and sternum

Correct answer: A

Rationale: The ball-and-socket joint is located between the upper arm (humerus) and the shoulder blade (scapula). This joint provides a wide range of motion, enabling movements like flexion, extension, abduction, adduction, and rotation. It plays a crucial role in various activities involving the shoulder joint, such as throwing, reaching overhead, and performing rotational movements. Choice B, the collarbone (clavicle) and breastbone (sternum), form the sternoclavicular joint, which is a synovial saddle joint. Choice C, two vertebrae in the spine, typically form gliding or facet joints. Choice D, ribs and sternum, are connected by cartilage, forming cartilaginous joints.

3. What property of a wave remains unchanged when it passes from one medium to another with the same speed?

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

Correct answer: A

Rationale: When a wave passes from one medium to another with the same speed, its frequency remains unchanged. Frequency is a characteristic of the source of the wave and does not depend on the medium through which the wave is traveling. Wavelength and speed of the wave can change when passing from one medium to another, but frequency remains constant. This is because the frequency of a wave is determined by the source that produces it, and as long as the speed remains constant, the frequency will not be altered. Amplitude, on the other hand, can change based on factors like energy loss or gain, but it is not a property that remains constant when a wave moves between different mediums with the same speed. Speed, although important for the wave's propagation, is not the property that remains unchanged when the wave transitions between mediums with the same speed. Therefore, the correct answer is frequency.

4. In order to be included in the formation of a scientific conclusion, evidence must be:

• A. Quantitative
• B. Reproducible
• C. Obvious
• D. All of the above

Correct answer: B

Rationale: For scientific evidence to be included in the formation of a scientific conclusion, it must be reproducible. Reproducibility is a fundamental aspect of the scientific method, ensuring that the same experiment will yield the same results if repeated. This allows other researchers to verify the findings and conclusions drawn from the evidence, enhancing the reliability and validity of the scientific process. While quantitative data can be important in supporting evidence, it is not a strict requirement for evidence to be included in scientific conclusions. The term 'obvious' is subjective and does not necessarily guarantee the reliability or reproducibility of the evidence, making it an unreliable criterion for scientific conclusions. Therefore, choice B, reproducible, is the correct answer as it aligns with the fundamental principles of the scientific method, emphasizing the importance of replicating results for establishing reliable conclusions.

5. Which macromolecules are composed of nucleotides and store information and energy?

• A. Lipids
• B. Proteins
• C. Carbohydrates
• D. Nucleic acids

Correct answer: D

Rationale: The correct answer is D: Nucleic acids. Nucleic acids, such as DNA and RNA, are composed of nucleotides and are responsible for storing genetic information and energy (e.g., ATP). Lipids, proteins, and carbohydrates are distinct macromolecules with varying functions and structures. Lipids primarily serve as energy reservoirs, structural components, and cell signaling molecules. Proteins play crucial roles in cellular functions like enzyme activity, structural support, and intracellular signaling. Carbohydrates are mainly utilized as an energy source and for structural purposes within cells.

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