Nursing Elites

1. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

• A. Frequency remains the same.
• B. Frequency is halved.
• C. Frequency is doubled.
• D. Frequency information is insufficient to determine.

Correct answer: B

Rationale: When the wavelength of a wave is doubled, and the speed of the wave remains constant, the frequency of the wave is halved. This relationship is governed by the equation speed = frequency x wavelength. Therefore, if the wavelength is doubled while the speed remains constant, the frequency must be halved to maintain a constant speed. Choice A is incorrect because frequency and wavelength are inversely proportional when speed is constant. Choice C is incorrect as doubling the wavelength does not result in a doubled frequency. Choice D is incorrect as the relationship between frequency, wavelength, and speed can be determined using the given information.

2. Which of the following is responsible for carrying electrical impulses in the nervous system?

• A. Platelets
• B. Neurons
• C. Red blood cells
• D. White blood cells

Correct answer: B

Rationale: Neurons are the correct answer as they are specialized cells in the nervous system that transmit electrical impulses throughout the body. Neurons have structures like axons and dendrites that enable the transmission of electrical signals. Platelets are responsible for blood clotting, red blood cells carry oxygen, and white blood cells are part of the immune system; however, none of these cell types play a role in carrying electrical impulses in the nervous system.

3. Enzymes are ________ molecules that serve as _______ for certain biological reactions.

• A. Enzymes are irrelevant molecules that serve as suppressors for certain biological reactions.
• B. Enzymes are acidic molecules that serve as catalysts for certain biological reactions.
• C. Enzymes are lipid molecules that serve as catalysts for certain biological reactions.
• D. Enzymes are protein molecules that serve as catalysts for certain biological reactions.

Correct answer: D

Rationale: Enzymes are protein molecules that serve as catalysts for certain biological reactions. Enzymes are biological molecules that speed up chemical reactions in living organisms by lowering the activation energy required for the reactions to occur. They are typically proteins that have specific shapes and active sites that allow them to interact with specific substrates and facilitate reactions without being consumed themselves. The other choices are incorrect because enzymes are not irrelevant, acidic, or lipid molecules; they are primarily proteins known for their catalytic properties.

4. Which of the following organs functions as both an endocrine and exocrine gland?

• A. The kidney
• B. The spleen
• C. The pancreas
• D. The stomach

Correct answer: C

Rationale: The pancreas is the correct answer as it functions as both an endocrine and exocrine gland. The endocrine function involves secreting insulin and glucagon into the bloodstream to regulate blood sugar levels, while the exocrine function involves releasing digestive enzymes into the small intestine to aid in digestion. The kidney (Choice A) primarily functions in the excretory system by filtering blood and producing urine. The spleen (Choice B) is involved in the immune system and blood storage but does not have endocrine or exocrine functions. The stomach (Choice D) is mainly an organ of the digestive system, secreting gastric juices to aid in digestion, but it does not have a dual endocrine and exocrine function like the pancreas.

5. What is the primary function of the CRISPR-Cas9 system in gene editing?

• A. To amplify specific DNA sequences.
• B. To cut DNA at specific locations.
• C. To deliver genes into cells.
• D. To sequence entire genomes.

Correct answer: B

Rationale: The CRISPR-Cas9 system is a powerful tool used in gene editing to precisely target and cut DNA at specific locations within the genome. This system consists of a guide RNA that directs the Cas9 enzyme to the desired DNA sequence, where it creates a double-strand break. This break can then be repaired by the cell's natural DNA repair mechanisms, allowing for the introduction of specific genetic modifications. Options A, C, and D are incorrect as they do not accurately describe the primary function of the CRISPR-Cas9 system in gene editing. Amplifying DNA sequences, delivering genes into cells, and sequencing entire genomes are not the main functions of the CRISPR-Cas9 system, which is primarily focused on precise DNA cutting for targeted genetic modifications.

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