Nursing Elites

1. Which of the following is produced by Natural Killer Cells to create pores for target cell rupture?

• A. Interferon
• B. Apoptosis
• C. Perforin
• D. Antibody

Correct answer: C

Rationale: The correct answer is C, Perforin. Natural Killer cells release perforin, which forms pores in the membrane of target cells, leading to their lysis. Interferon (choice A) is a protein released by cells in response to viral infections, apoptosis (choice B) is programmed cell death, and antibodies (choice D) are produced by B cells to neutralize pathogens but are not directly involved in creating pores for cell rupture like perforin.

2. A botanist wants to determine if environmental temperature affects root growth. What is the independent variable in this study?

• A. Temperature
• B. Seedlings
• C. Light
• D. Root length

Correct answer: A

Rationale: The correct answer is 'Temperature.' In an experiment, the independent variable is the factor that is deliberately manipulated or changed by the researcher. In this study, the botanist is specifically investigating how environmental temperature affects root growth, making temperature the independent variable. Choice B, 'Seedlings,' and Choice C, 'Light,' are not the independent variables in this context as they are not the factors being intentionally changed or manipulated. Choice D, 'Root length,' is the dependent variable, as it is the outcome that is being measured or observed in response to the changes in the independent variable, temperature.

3. What is the main consequence of a malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones?

• A. Increased energy levels and weight loss
• B. Decreased heart rate and body temperature
• C. Enhanced muscle growth and bone development
• D. Faster metabolism and heightened alertness

Correct answer: B

Rationale: The correct answer is B: Decreased heart rate and body temperature. A malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones leads to hypothyroidism, resulting in decreased metabolic activity. This reduction in metabolic rate can cause a decreased heart rate and lower body temperature. Choices A, C, and D are incorrect because hypothyroidism typically manifests as symptoms such as fatigue, weight gain, cold intolerance, bradycardia, and decreased body temperature, rather than increased energy levels, enhanced muscle growth, faster metabolism, or heightened alertness.

4. What is the principle behind the phenomenon of refraction, where waves bend when entering a new medium?

• A. Change in wavelength
• B. Change in frequency
• C. Change in wave speed
• D. None of the above

Correct answer: C

Rationale: Refraction occurs due to a change in wave speed when waves enter a new medium. As waves travel from one medium to another, their speed changes, causing them to bend. This change in speed is responsible for the bending of waves during refraction. It is not the change in wavelength or frequency that causes refraction, but rather the change in speed as waves move through different mediums. Therefore, the correct answer is the change in wave speed (Choice C). Choices A and B are incorrect as refraction is not primarily influenced by changes in wavelength or frequency, but by changes in wave speed. Choice D is also incorrect as there is a specific principle, which is the change in wave speed, behind the phenomenon of refraction.

5. Which of the following is NOT a tissue layer found in skeletal bone?

• A. periosteum
• B. bone marrow
• C. enamel
• D. cancellous bone

Correct answer: C

Rationale: Enamel is a hard, outer layer that covers the crown of a tooth and is not a tissue layer found in skeletal bone. The other options, periosteum, bone marrow, and cancellous bone, are all tissue layers or components found in skeletal bone. Periosteum is the connective tissue layer covering the bone surface, bone marrow is found within the bone cavities, and cancellous bone is a spongy, porous bone tissue.

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