Nursing Elites

1. What term refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction?

• A. Sarcomere
• B. Synapse
• C. Tendon
• D. Myofibril

Correct answer: B

Rationale: The correct answer is B, 'Synapse.' The synapse is the specific term that refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction. At the synapse, neurotransmitters are released by the motor neuron, triggering the muscle fiber to contract. Choice A, 'Sarcomere,' is incorrect as a sarcomere is the basic unit of muscle contraction, not the point of contact between a motor neuron and a muscle fiber. Choice C, 'Tendon,' is incorrect as tendons are fibrous connective tissues that connect muscle to bone, not involved in neuronal communication. Choice D, 'Myofibril,' is incorrect as a myofibril is a structure within muscle fibers where muscle contractions occur, not the specific point of contact for communication between a motor neuron and a muscle fiber.

2. According to the periodic table, which of the following elements is the least reactive?

• A. Fluorine
• B. Silicon
• C. Neon
• D. Gallium

Correct answer: C

Rationale: Neon is the least reactive among the given elements because it belongs to the noble gases group in the periodic table. Noble gases have a full valence shell of electrons, making them highly stable and least likely to react with other elements. Fluorine is the most reactive non-metal due to its high electronegativity. Silicon is a metalloid with moderate reactivity, falling between metals and nonmetals. Gallium is a metal with higher reactivity compared to Neon, but it is not as reactive as Fluorine.

3. Which of the following organs is responsible for churning and mechanically breaking down food?

• A. Small intestine
• B. Large intestine
• C. Stomach
• D. Esophagus

Correct answer: C

Rationale: The correct answer is C, the stomach. The stomach is responsible for churning and mechanically breaking down food. It contains muscles that contract and relax to mix food with digestive juices, breaking it down into smaller particles. This mechanical digestion process helps prepare the food for further digestion and absorption in the small intestine. The small intestine is primarily responsible for the absorption of nutrients, not for mechanical digestion. The large intestine absorbs water and salts, and the esophagus is a muscular tube that transports food from the mouth to the stomach, not involved in churning or breaking down food.

4. Which of the following organelles is responsible for protein production in the cell?

• A. Ribosomes
• B. Golgi apparatus
• C. Mitochondria
• D. Lysosomes

Correct answer: A

Rationale: The correct answer is A: Ribosomes. Ribosomes are the organelles responsible for protein synthesis in the cell. They can be found either freely floating in the cytoplasm or attached to the endoplasmic reticulum. The Golgi apparatus (Choice B) is involved in processing and packaging proteins, not protein production. Mitochondria (Choice C) are responsible for energy production, not protein synthesis. Lysosomes (Choice D) are involved in digestion and waste removal, not protein production.

5. What is the term for an organism with two different alleles for a gene?

• A. Homozygous
• B. Heterozygous
• C. Dominant
• D. Recessive

Correct answer: B

Rationale: Homozygous refers to an organism with two identical alleles for a gene, either both dominant or both recessive. Heterozygous, the correct answer, refers to an organism with two different alleles for a gene, one dominant and one recessive. Dominant and recessive describe the relationship between alleles, where dominant alleles are expressed over recessive alleles in heterozygous individuals. Therefore, the term for an organism with two different alleles for a gene is 'heterozygous.'

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