Nursing Elites

1. When ice melts, it undergoes a...

• A. Chemical change
• B. Physical change
• C. Nuclear change
• D. Radioactive decay

Correct answer: B

Rationale: When ice melts, it undergoes a physical change, transitioning from a solid state to a liquid state. This change does not involve altering the chemical composition of the ice, making it a physical change rather than a chemical change, nuclear change, or radioactive decay. Choice A, 'Chemical change,' is incorrect because a chemical change involves a rearrangement of atoms resulting in new substances. Choice C, 'Nuclear change,' is incorrect as it refers to changes in the nucleus of an atom, not the phase transition of ice. Choice D, 'Radioactive decay,' is incorrect as it involves the spontaneous disintegration of an unstable atomic nucleus, which is not the process occurring when ice melts.

2. What is the role of RNA in protein synthesis?

• A. Stores genetic information
• B. Decodes genetic information
• C. Provides energy for the process
• D. Transports amino acids to the ribosomes

Correct answer: B

Rationale: RNA plays a crucial role in protein synthesis by decoding the genetic information stored in DNA and carrying it to the ribosomes where proteins are synthesized. This process involves transcription, where RNA is synthesized from DNA, and translation, where the information in RNA is used to assemble amino acids into proteins. RNA acts as a messenger between DNA and the ribosomes, ensuring that the correct sequence of amino acids is used to build proteins according to the genetic code. Option A is incorrect because DNA, not RNA, stores genetic information. Option C is incorrect because RNA does not provide energy for protein synthesis; energy is usually provided by ATP molecules. Option D is incorrect because tRNA (transfer RNA) is responsible for transporting amino acids to the ribosomes, not RNA in general. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in protein synthesis.

3. What is the primary hormone released by the parathyroid glands?

• A. Insulin
• B. Calcitonin
• C. Parathyroid hormone (PTH)
• D. Thyroxine

Correct answer: C

Rationale: The primary hormone released by the parathyroid glands is parathyroid hormone (PTH). PTH plays a crucial role in regulating calcium and phosphorus levels in the body by increasing calcium levels in the blood through various mechanisms, such as promoting calcium release from bones and increasing calcium absorption in the intestines. Insulin is produced by the pancreas and regulates blood sugar levels, calcitonin is produced by the thyroid gland and helps lower blood calcium levels, and thyroxine is a hormone produced by the thyroid gland that regulates metabolism. Therefore, choices A, B, and D are incorrect as they are not the primary hormone released by the parathyroid glands.

4. Which of the following structures plays a crucial role in controlling the cell cycle and preventing uncontrolled cell growth?

• A. The centrioles
• B. The nucleolus
• C. The Golgi apparatus
• D. The endoplasmic reticulum

Correct answer: A

Rationale: The correct answer is A: The centrioles. Centrioles are cylindrical structures found in animal cells that are crucial in organizing the spindle fibers during cell division (mitosis). They play a vital role in separating chromosomes during cell division, ensuring each daughter cell receives the correct number of chromosomes. Additionally, centrioles are involved in the formation of cilia and flagella, essential for cell motility and sensory functions. The nucleolus is responsible for ribosome production, the Golgi apparatus processes and packages proteins, and the endoplasmic reticulum is involved in protein synthesis and lipid metabolism. These structures do not have a direct role in controlling the cell cycle and preventing uncontrolled cell growth.

5. Which of the following is the main function of the skin?

• A. To protect the body from harm
• B. To regulate body temperature
• C. To produce hormones
• D. To sense touch, temperature, and pain

Correct answer: A

Rationale: Rationale: A) To protect the body from harm: The skin acts as a physical barrier that protects the body from external threats such as pathogens, UV radiation, and physical injuries. It helps prevent infections and dehydration, making it a crucial function of the skin. B) To regulate body temperature: While the skin does play a role in regulating body temperature through processes like sweating and vasodilation/vasoconstriction, its primary function is protection. C) To produce hormones: Hormone production is primarily carried out by endocrine glands such as the pituitary gland, thyroid gland, and adrenal glands, not the skin. D) To sense touch, temperature, and pain: The skin contains sensory receptors that allow us to perceive touch, temperature, and pain, but this function is secondary to its main role of protecting the body from harm.

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