Nursing Elites

1. What is the coefficient of oxygen in the balanced chemical equation for the combustion of methane (CH₄)?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: In the balanced chemical equation for the combustion of methane, CH₄ + 2O₂ → CO₂ + 2H₂O, the coefficient of oxygen (O₂) is 2. This indicates that two molecules of oxygen are required to react with one molecule of methane to produce carbon dioxide and water, ensuring the equation is balanced. Choice A is incorrect because the coefficient of oxygen is not 1 but 2. Choices C and D are incorrect as they do not represent the correct coefficient of oxygen in the balanced equation. Understanding the coefficients in a balanced chemical equation is crucial for accurately representing the stoichiometry of the reaction.

2. Which of the following substances is NOT a product of cellular respiration?

• A. Carbon dioxide
• B. Water
• C. Oxygen
• D. ATP

Correct answer: C

Rationale: The correct answer is C. Oxygen is not a product of cellular respiration; instead, it is consumed during the process. During cellular respiration, glucose is broken down in the presence of oxygen to produce energy in the form of ATP, carbon dioxide, and water. Carbon dioxide is released as a waste product, water is a byproduct of the chemical reactions, and ATP is the energy currency used by cells. Therefore, options A, B, and D are all products or outcomes of cellular respiration, while oxygen is a reactant.

3. The process by which two or more species reciprocally influence each other's evolution through selection pressures exerted on one another is called:

• A. Convergent evolution
• B. Divergent evolution
• C. Coevolution
• D. Coevolution

Correct answer: C

Rationale: A) Convergent evolution refers to the process by which unrelated species evolve similar traits due to similar environmental pressures. This does not involve reciprocal influence between species. B) Divergent evolution refers to the process by which two or more related species become more dissimilar over time due to different selection pressures. This also does not involve reciprocal influence between species. C) Coevolution is the process by which two or more species reciprocally influence each other's evolution through selection pressures exerted on one another. This can lead to a close ecological relationship between the species, such as in predator-prey interactions or mutualistic relationships. D) This option is a duplicate of option C.

4. A rocket blasts off from Earth. What is the main force propelling the rocket upwards?

• A. Gravitational force
• B. Air resistance
• C. Thrust from the rocket engine
• D. Normal force from the launchpad

Correct answer: C

Rationale: The main force propelling the rocket upwards is the thrust from the rocket engine. Thrust is the force produced by the rocket engine pushing exhaust gases in the opposite direction, following Newton's third law of motion (action and reaction). This thrust overcomes the force of gravity and allows the rocket to lift off and move upwards. Choice A, gravitational force, is incorrect as gravity pulls objects towards the Earth, and in this case, the rocket is moving against gravity. Choice B, air resistance, is incorrect because it opposes the motion of the rocket and is more relevant during descent rather than ascent. Choice D, normal force from the launchpad, is incorrect as this force acts perpendicular to the surface and does not propel the rocket upwards.

5. What is the monomer for nucleic acids?

• A. Nucleotide
• B. Amino acid
• C. Phosphate group
• D. Ribosome

Correct answer: A

Rationale: The correct answer is A: Nucleotide. Nucleotides are indeed the monomers that make up nucleic acids like DNA and RNA. They consist of a sugar molecule, a phosphate group, and a nitrogenous base. Amino acids are the monomers of proteins, not nucleic acids. While the phosphate group is a component of nucleotides, it is not the sole monomer. Ribosome is a cellular organelle involved in protein synthesis and is not a monomer for nucleic acids.

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