Nursing Elites

1. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

• A. The rate of mutation is constant across all genes and all species.
• B. Species with more morphological similarities diverged more recently.
• C. Mutations are always beneficial and contribute to increased fitness.
• D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

2. What term describes the bouncing back of waves after striking a surface or boundary?

• A. Diffraction
• B. Refraction
• C. Reflection
• D. Interference

Correct answer: C

Rationale: The correct answer is 'Reflection.' Reflection is the term used to describe the bouncing back of waves after striking a surface or boundary. Diffraction, on the other hand, refers to the bending of waves around obstacles. Refraction is the bending of waves as they pass from one medium to another. Interference involves the combination of two or more waves that results in a new wave pattern. Therefore, in this context, choices A, B, and D are incorrect as they do not specifically relate to the bouncing back of waves after striking a surface or boundary.

3. A gift box has a length of 14 inches, a height of 8 inches, and a width of 6 inches. How many square inches of wrapping paper are needed to wrap the box?

• A. 56
• B. 244
• C. 488
• D. 672

Correct answer: C

Rationale: To find the surface area of a rectangular prism, you use the formula SA = 2lw + 2wh + 2hl, where l is the length, w is the width, and h is the height. Substituting the given dimensions, the calculation would be SA = 2(14)(6) + 2(6)(8) + 2(8)(14) = 168 + 96 + 224 = 488 square inches. Therefore, 488 square inches of wrapping paper are needed to wrap the box. Choice A (56), Choice B (244), and Choice D (672) are incorrect because they do not represent the correct surface area calculation for the given box dimensions.

4. Which of the following numbers has the greatest value?

• A. 1.4378
• B. 1.07548
• C. 1.43592
• D. 0.89409

Correct answer: B

Rationale: To determine the number with the greatest value among the options, focus on the digit in the tenths place. In this case, 1.07548 has the highest value as it has the digit 7 in the tenths place. Comparing this to the other numbers, 1.4378, 1.43592, and 0.89409 have 4, 3, and 8 in the tenths place, respectively. Therefore, 1.07548 is the number with the greatest value as it has the highest digit in the tenths place.

5. Which part of the eye controls the amount of light that enters the eye?

• A. Cornea
• B. Iris
• C. Retina
• D. Lens

Correct answer: B

Rationale: The iris is the correct answer as it controls the amount of light that enters the eye by adjusting the size of the pupil. The cornea is responsible for focusing light onto the retina, the retina detects light at the back of the eye, and the lens helps in further focusing light onto the retina. The iris, through changing the size of the pupil, regulates the amount of light reaching the eye, making it the part that controls the entry of light.

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