Nursing Elites

1. When sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl), the resulting product is:

• A. Hydrogen gas and sodium chloride (NaCl)
• B. Chlorine gas and sodium oxide (Na2O)
• C. Sodium metal (Na) and water (H2O)
• D. No reaction occurs.

Correct answer: A

Rationale: When sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl), a neutralization reaction occurs. The products of this reaction are water (H2O) and a salt, which is sodium chloride (NaCl). The chemical equation for this reaction is: NaOH + HCl -> NaCl + H2O. Choice B is incorrect because chlorine gas and sodium oxide are not the products of this reaction. Choice C is incorrect as sodium metal and water are not the products formed in this neutralization reaction. Choice D is incorrect because a reaction does occur between NaOH and HCl, resulting in the formation of NaCl and H2O. Therefore, the correct answer is A: Hydrogen gas and sodium chloride (NaCl).

2. The Gram stain is a differential staining technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria appear

• A. Pink
• B. Blue
• C. Red
• D. Purple

Correct answer: D

Rationale: The Gram stain is a differential staining technique that categorizes bacteria into two groups based on their cell wall composition: Gram-positive and Gram-negative. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain used in the Gram staining procedure. Consequently, Gram-positive bacteria appear purple under the microscope after staining. On the other hand, Gram-negative bacteria possess a thinner peptidoglycan layer and an outer membrane that can be penetrated by the counterstain safranin, leading them to appear pink or red. Blue is not typically used to describe the color of bacteria in a Gram stain, making it an incorrect choice.

3. What is the basic unit of communication in the nervous system?

• A. Neuron
• B. Astrocyte
• C. Neurotransmitter
• D. Synapse

Correct answer: A

Rationale: A neuron is the basic unit of communication in the nervous system. Neurons are specialized cells responsible for transmitting information through electrical and chemical signals. Astrocytes are a type of glial cell that provide support and nourishment to neurons but do not participate in signal transmission. Neurotransmitters are chemicals that facilitate signal transmission between neurons, and synapses are the specific junctions where these signals are transmitted. Therefore, the correct answer is 'A: Neuron' as it is the primary cell involved in transmitting information in the nervous system.

4. Deuterium, a stable isotope of hydrogen, has a nucleus containing:

• A. A single proton
• B. A proton and a neutron
• C. Two protons and an electron
• D. Two neutrons

Correct answer: B

Rationale: Deuterium, as an isotope of hydrogen, has an atomic number of 1 and a mass number of 2. The nucleus of deuterium contains one proton (as in all hydrogen atoms) and one neutron, totaling 2 nucleons in the nucleus. Therefore, the correct answer is that deuterium's nucleus contains a proton and a neutron. Choices A, C, and D are incorrect. Deuterium is not just a single proton (A), doesn't have two protons and an electron (C), and doesn't contain two neutrons (D). The correct composition of deuterium's nucleus is one proton and one neutron.

5. Which of the following hormones is primarily responsible for regulating metabolism?

• A. Insulin
• B. Testosterone
• C. Adrenaline
• D. Thyroid hormone

Correct answer: D

Rationale: Thyroid hormone is the correct answer as it is primarily responsible for regulating metabolism. It plays a crucial role in controlling the body's metabolic rate, affecting how the body uses energy from food. Thyroid hormone levels can influence metabolism, energy production, and body weight regulation. Insulin, choice A, is involved in regulating blood sugar levels, not directly metabolism. Testosterone, choice B, is a sex hormone that primarily affects the development of male reproductive tissues. Adrenaline, choice C, is involved in the fight-or-flight response and not primarily responsible for regulating metabolism.

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