Nursing Elites

1. What is a reaction between an acid and a base known as?

• A. Precipitation
• B. Neutralization
• C. Oxidation-reduction
• D. Photolysis

Correct answer: B

Rationale: The correct answer is B: Neutralization. When an acid and a base react, they neutralize each other's properties, resulting in the formation of water and a salt. Choice A, 'Precipitation,' refers to the formation of a solid from a solution during a chemical reaction. Choice C, 'Oxidation-reduction,' involves the transfer of electrons between reactants. Choice D, 'Photolysis,' is a reaction where a compound is broken down into smaller components by light energy. Therefore, the most appropriate term for a reaction between an acid and a base is neutralization.

2. Which of the following statements regarding the working of the heart is not correct?

• A. The atria contract, and the valves open to allow blood into the ventricles.
• B. The heartbeat begins when the heart muscles relax, and blood flows into the atria.
• C. The valves close to stop blood from flowing backward.
• D. The ventricles contract, forcing blood to leave the heart.

Correct answer: B

Rationale: The correct answer is B because the heartbeat actually begins when the heart muscles relax, allowing the chambers to fill with blood. The contraction phase follows, which propels blood out of the heart. The other statements are accurate in describing the normal sequence of events in the heart's functioning: the atria contract to push blood into the ventricles, the valves close to prevent backflow of blood, and the ventricles contract to pump blood out of the heart.

3. How will mildly elevated levels of thyroxine affect the heart rate?

• A. Stop the heart rate
• B. No effect
• C. Decrease the heart rate
• D. Increase the heart rate

Correct answer: D

Rationale: Mildly elevated levels of thyroxine will increase the heart rate. Thyroxine, a hormone produced by the thyroid gland, regulates metabolism. Elevated thyroxine levels can lead to increased metabolism, resulting in an elevated heart rate. Choice A is incorrect as mildly elevated thyroxine levels do not stop the heart rate. Choice B is incorrect because elevated thyroxine levels do have an effect on heart rate. Choice C is incorrect as elevated thyroxine levels typically lead to an increase rather than a decrease in heart rate.

4. The muscular diaphragm plays a vital role in respiration. When it contracts, it:

• A. Increases lung volume for inhalation
• B. Decreases lung volume for exhalation
• C. Filters dust and particles from inhaled air
• D. Produces mucus to lubricate the airways

Correct answer: A

Rationale: The muscular diaphragm plays a crucial role in respiration by contracting and flattening during inhalation. This action increases the volume of the thoracic cavity, which leads to a decrease in pressure within the lungs, allowing air to rush in and fill the expanded space. Choice B is incorrect because the diaphragm contracting increases the lung volume for inhalation, not decreases it for exhalation. Choice C is incorrect as the role of filtering dust and particles is primarily performed by the respiratory system's other structures like the nasal passages and the mucous membranes. Choice D is incorrect as mucus production is mainly carried out by specialized cells in the respiratory system and not by the diaphragm.

5. Two mice are both heterozygous for two traits: white fur (Ww) and short fur (Ss). Their offspring are most likely to have which of the following genotypes for these traits?

• A. wwss
• B. WWSS
• C. WwSs
• D. WWSs

Correct answer: C

Rationale: When two mice that are heterozygous for white fur (Ww) and short fur (Ss) mate, they can produce offspring with different combinations of the two traits. The Punnett square for this cross shows that the most likely genotype for the offspring is WwSs. In this case, each offspring receives one allele for white fur (W) and one for short fur (S) from each parent, resulting in a heterozygous genotype for both traits. Choice A (wwss) is incorrect as it represents a homozygous recessive genotype for both traits. Choice B (WWSS) is also incorrect as it represents a homozygous dominant genotype for both traits. Choice D (WWSs) is incorrect as it represents a genotype where one trait is homozygous dominant (W) and the other is heterozygous (S), which is not the most likely outcome based on the given parental genotypes.

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