Nursing Elites

1. What is the building block of RNA?

• A. Amino acid
• B. Nucleotide
• C. Protein
• D. Fatty acid

Correct answer: B

Rationale: Rationale: A) Amino acid: Amino acids are the building blocks of proteins, not RNA. B) Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.

2. A hypothesis should be:

• A. A definitive statement of fact based on existing knowledge.
• B. A testable prediction based on observations and reasoning.
• C. A broad question without any specific direction or focus.
• D. A personal belief or opinion not requiring further investigation.

Correct answer: B

Rationale: Hypotheses guide scientific exploration by providing a framework for testing potential explanations.

3. What is the principle behind the phenomenon of refraction, where waves bend when entering a new medium?

• A. Change in wavelength
• B. Change in frequency
• C. Change in wave speed
• D. None of the above

Correct answer: C

Rationale: Refraction occurs because of the change in wave speed as it enters a new medium, causing the wavefront to bend and change direction.

4. What is the process by which decomposers break down organic matter?

• A. Photosynthesis
• B. Bioremediation
• C. Decomposition
• D. Nitrification

Correct answer: C

Rationale: Rationale: A) Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy to produce glucose from carbon dioxide and water. This process is not related to the breakdown of organic matter by decomposers. B) Bioremediation is the use of living organisms to clean up contaminated environments. While it involves the use of microorganisms to break down pollutants, it is not specifically focused on breaking down organic matter. C) Decomposition is the process by which decomposers such as bacteria, fungi, and other organisms break down organic matter into simpler substances. This process is essential for nutrient recycling in ecosystems. D) Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of nitrite to nitrate by nitrifying bacteria. This process is part of the nitrogen cycle and is not directly related to the breakdown of organic matter.

5. The number of protons in the nucleus of an atom determines its:

• A. Mass number
• B. Atomic number
• C. Isotope
• D. Valence electron count

Correct answer: B

Rationale: The atomic number (Z) equals the number of protons in the nucleus and uniquely identifies an element. Mass number (A) includes both protons and neutrons, isotopes have different neutron numbers, and valence electrons are involved in bonding, not atomic identity.

6. A keystone species plays a critical role in an ecosystem because its removal would:

• A. Lead to a decrease in competition among other species
• B. Cause a slight increase in primary productivity
• C. Have a minimal impact on the overall ecosystem structure
• D. Disrupt the food web and cause cascading effects on other populations

Correct answer: D

Rationale: Rationale: Keystone species are species that have a disproportionately large effect on their environment relative to their abundance. They play a critical role in maintaining the structure and function of an ecosystem. If a keystone species is removed from an ecosystem, it can disrupt the food web by causing imbalances in predator-prey relationships. This disruption can lead to cascading effects on other populations within the ecosystem, potentially causing population declines or even extinctions. Therefore, the removal of a keystone species would have significant impacts on the overall ecosystem structure, making option D the correct answer.

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