Nursing Elites

1. At the peak of its trajectory, what force is acting on a ball thrown upwards?

• A. Gravity only
• B. Gravity and air resistance only
• C. Neither gravity nor air resistance
• D. All of the above

Correct answer: A

Rationale: At the peak of its trajectory, the ball momentarily stops moving upwards before it starts to fall back down. At this point, the only force acting on the ball is gravity, pulling it back towards the ground. Air resistance is negligible at the peak of the trajectory as the ball is momentarily stationary. Therefore, the correct answer is 'Gravity only.' Choices B, C, and D are incorrect. Option B is incorrect because air resistance is minimal when the ball is at its highest point and its velocity is nearly zero. Option C is incorrect as gravity is the only significant force acting on the ball at that instant. Option D is incorrect since air resistance is not a significant factor at the peak of the trajectory.

2. Electrons occupy specific energy levels around the nucleus, but not in fixed orbits. This concept is captured by the:

• A. Bohr model
• B. Quantum mechanical model
• C. Lewis structure
• D. Octet rule

Correct answer: B

Rationale: The correct answer is the Quantum mechanical model. Unlike the Bohr model with its defined electron paths, the quantum mechanical model uses probability distributions to describe electron locations within energy levels. Choice A, the Bohr model, describes fixed electron orbits, which is not in line with the concept of electron distribution in energy levels. Choices C and D, Lewis structure and Octet rule respectively, are not related to the description of electron distribution around the nucleus in energy levels, making them incorrect answers.

3. In an experiment where five tropical plants are kept at varying humidity levels in a greenhouse for three months, while one plant is left outside in normal conditions, with plant height measured weekly, what serves as the control of the experiment?

• A. Plant height for each tropical plant
• B. The plant left outside in normal conditions
• C. Humidity level readings in the greenhouse
• D. Amount of time used to study plant height

Correct answer: B

Rationale: The correct answer is B. The plant left outside in normal conditions acts as the control in the experiment. It provides a standard reference point for comparison to assess the impact of the varying humidity levels on the growth of the tropical plants. Choice A is incorrect because it refers to the dependent variable being measured, not the control. Choice C is incorrect as humidity levels in the greenhouse are part of the experimental conditions, not the control. Choice D is incorrect as the time used for studying plant height is a parameter of the experiment and not the control.

4. What is the main function of vacuoles in plant cells?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store water, enzymes, and waste products

Correct answer: D

Rationale: Vacuoles in plant cells primarily function as storage organelles. They store water, enzymes, pigments, and waste products, helping to maintain turgor pressure within the cell. This turgor pressure provides structural support for the plant cell. While vacuoles can also participate in transporting substances within the cell, their main role is storage. The synthesis of proteins and lipids is mainly handled by other organelles such as the endoplasmic reticulum and Golgi apparatus. Choice A is incorrect because while vacuoles indirectly contribute to structural support by maintaining turgor pressure, their primary function is storage. Choice B is incorrect as vacuoles are not primarily responsible for transporting substances in and out of the cell. Choice C is incorrect as vacuoles do not synthesize proteins and lipids; this function is carried out by other organelles.

5. What is one feature that both prokaryotes and eukaryotes have in common?

• A. A plasma membrane
• B. A nucleus enclosed by a membrane
• C. Organelles
• D. A nucleoid

Correct answer: A

Rationale: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes share the characteristic of having a plasma membrane that surrounds the cell. While eukaryotes also possess a nucleus enclosed by a membrane and various organelles, prokaryotes lack a nucleus and membrane-bound organelles. The plasma membrane, however, is a universal feature found in all cells, regardless of their classification as prokaryotic or eukaryotic. Choice B is incorrect because only eukaryotes have a nucleus enclosed by a membrane. Choice C is incorrect because prokaryotes have limited organelles compared to eukaryotes. Choice D is incorrect as a nucleoid is a region in prokaryotic cells where the genetic material is located, not a common feature shared with eukaryotes.

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