Nursing Elites

1. Where does the nerve impulses send neurotransmitters across a synapse to a muscle cell to stimulate muscle contraction?

• A. sarcomere
• B. tendon
• C. myelin sheath
• D. neuromuscular junction

Correct answer: D

Rationale: The neuromuscular junction is the specific area where nerve impulses trigger the release of neurotransmitters that cross the synaptic gap to bind to receptors on the muscle cell membrane. This binding initiates muscle contraction by stimulating the muscle cell. The sarcomere is the basic contractile unit in a muscle fiber, not the location where nerve impulses communicate with muscle cells. Tendons are connective tissues that attach muscles to bones and are not involved in transmitting nerve impulses. The myelin sheath is a protective covering around nerve fibers but is not directly involved in transmitting neurotransmitters to muscle cells for muscle contraction.

2. What property of a wave determines its speed in a given medium?

• A. Amplitude
• B. Wavelength
• C. Frequency
• D. Medium's properties

Correct answer: D

Rationale: The speed of a wave in a given medium is determined by the properties of that medium, such as its density and elasticity. While amplitude, wavelength, and frequency are important characteristics of a wave, they do not directly impact its speed in a specific medium. Amplitude refers to the maximum displacement of particles in a wave, wavelength is the distance between two successive points in a wave that are in phase, and frequency is the number of complete oscillations a wave makes in a given time. However, these properties do not dictate the speed of a wave in a particular medium. Therefore, the correct answer is the medium's properties.

3. What is the role of transfer RNA (tRNA) in protein synthesis?

• A. Transcribes DNA into mRNA
• B. Decodes the genetic code on mRNA
• C. Carries specific amino acids to the ribosomes
• D. Modifies the structure of proteins

Correct answer: C

Rationale: A) Transcribes DNA into mRNA: This is the function of RNA polymerase, not transfer RNA (tRNA). tRNA is involved in protein synthesis, not transcription. B) Decodes the genetic code on mRNA: This is the function of tRNA during translation. tRNA molecules carry specific amino acids and recognize the codons on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. C) Carries specific amino acids to the ribosomes: This is the primary role of tRNA in protein synthesis. Each tRNA molecule is specific for a particular amino acid and carries it to the ribosome, where it is added to the growing protein chain. D) Modifies the structure of proteins: This is not a function of tRNA. Protein modification can occur after translation is complete and involves other cellular processes and molecules.

4. Identify the function NOT attributed to the lymphatic system.

• A. Fluid drainage from tissues
• B. Immune response via white blood cell production
• C. Nutrient transport throughout the body
• D. Waste removal through lymph nodes

Correct answer: C

Rationale: A) Fluid drainage from tissues: This function is attributed to the lymphatic system. Lymphatic vessels collect excess fluid from tissues and return it to the bloodstream. B) Immune response via white blood cell production: The lymphatic system plays a crucial role in the body's immune response by producing and transporting white blood cells, such as lymphocytes, which help fight infections. C) Nutrient transport throughout the body: Nutrient transport is primarily carried out by the circulatory system (blood vessels), not the lymphatic system. The circulatory system transports nutrients, oxygen, and hormones to cells and removes waste products. D) Waste removal through lymph nodes: The lymphatic system helps remove waste and toxins from the body by filtering lymph through lymph nodes, where harmful substances are trapped and destroyed by immune cells. Therefore, the function NOT attributed to the lymphatic system is C) Nutrient transport throughout the body.

5. What is the term for the energy absorbed during a chemical reaction?

• A. Kinetic energy
• B. Potential energy
• C. Heat energy
• D. Endothermic energy

Correct answer: D

Rationale: The correct term for the energy absorbed during a chemical reaction is 'Endothermic energy.' Endothermic reactions absorb energy from their surroundings, leading to a decrease in temperature. The prefix 'endo-' means 'inward' or 'within,' indicating that energy is taken in during the reaction. Choices A, B, and C are incorrect because kinetic energy refers to the energy of motion, potential energy is stored energy, and heat energy is a form of energy transfer rather than specifically the energy absorbed during a chemical reaction.

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