Nursing Elites

1. A spring with a spring constant of 100 N/m is stretched 0.2 m from its equilibrium position. What is the potential energy stored in the spring?

• A. 2 J
• B. 4 J
• C. 8 J
• D. 20 J

Correct answer: C

Rationale: The potential energy stored in a spring is given by the formula \(PE = \frac{1}{2}kx^2\), where \(k\) is the spring constant and \(x\) is the displacement from the equilibrium position. Substituting the given values, we get \(PE = \frac{1}{2} \times 100 \times (0.2)^2 = 8\) J.

2. DNA has both a 'sense' and 'antisense' strand. What is true about the antisense strand?

• A. It runs 5' to 3'.
• B. It runs 3' to 5'.
• C. It is used in replication.
• D. It is the direction in which DNA is stored.

Correct answer: B

Rationale: The correct answer is B. The antisense strand runs 3' to 5', which is opposite to the direction of the sense strand. It serves as the template strand for transcription, where an RNA molecule is synthesized complementary to the antisense strand. Choice A is incorrect because the antisense strand runs in the opposite direction. Choice C is incorrect as the antisense strand is primarily involved in transcription, not replication. Choice D is incorrect as the direction of DNA storage is not determined by the antisense strand.

3. Which type of blood vessel carries blood away from the heart?

• A. Vein
• B. Artery
• C. Capillary
• D. Venule

Correct answer: B

Rationale: The correct answer is B: Artery. Arteries carry oxygen-rich blood away from the heart to various parts of the body. Veins, on the other hand, carry blood back to the heart. Capillaries are tiny blood vessels where oxygen and nutrients are exchanged with tissues. Venules are small veins that collect blood from capillaries, not from the heart, making them incorrect in this context.

4. The Hardy-Weinberg equilibrium describes a population that is:

• A. Undergoing rapid evolution due to strong directional selection.
• B. Not evolving and at genetic equilibrium with stable allele frequencies.
• C. Experiencing a founder effect leading to a reduction in genetic diversity.
• D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

5. What correction should the student make to the hypothesis: Lengthening the string of the pendulum increases the time it takes the ball to make one complete period?

• A. Turn it into an 'if-then' statement.
• B. Change 'will increase' to 'increases.'
• C. Switch the order of the sentence so that the phrase about the period comes first.
• D. No corrections are needed.

Correct answer: A

Rationale: The correct answer is A. A hypothesis should be structured as an 'if-then' statement for clarity. This format helps to clearly establish the relationship between the variables and the expected outcome. In this case, the student should frame the hypothesis in a way that if a specific action is taken (lengthening the string), then a specific outcome is expected (increasing the time it takes for the ball to make one complete period). 'If-then' statements are fundamental in hypothesis construction as they clearly define the cause and effect relationship being tested. Choice B is incorrect because changing 'will increase' to 'increases' does not address the structural issue of the hypothesis. Choice C is incorrect as switching the order of the sentence does not fundamentally alter the clarity of the hypothesis. Choice D is incorrect as the hypothesis structure can be improved for better understanding and testing, making correction necessary.

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