Nursing Elites

1. Which cellular structure is found in animal cells but not in plant cells?

• A. Centriole
• B. Cytoplasm
• C. Vacuole
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A, Centriole. Centrioles are found in animal cells but not in plant cells. They play a crucial role in organizing microtubules during cell division, aiding in the formation of the mitotic spindle. Plant cells lack centrioles; instead, they utilize microtubule organizing centers to perform similar functions during cell division. Choices B, C, and D are incorrect because cytoplasm is a part of both animal and plant cells, vacuoles are found in plant cells and some animal cells, and the Golgi apparatus is present in both types of cells.

2. What are the three main events of the haploid cell cycle?

• A. DNA replication, mitosis, and cytokinesis
• B. DNA replication, meiosis, and cytokinesis
• C. DNA replication, cytokinesis, and degradation
• D. Mitosis, meiosis, and apoptosis

Correct answer: A

Rationale: In the haploid cell cycle, the three main events are DNA replication, where the cell's genetic material is duplicated; mitosis, which is the division of the nucleus to ensure each daughter cell receives a complete set of chromosomes; and cytokinesis, the division of the cell cytoplasm to separate the two daughter cells. Meiosis is not part of the haploid cell cycle as it occurs in diploid cells to produce haploid gametes. Apoptosis is a process of programmed cell death and is not a routine event in the cell cycle. Therefore, the correct answer is A. Choices B, C, and D are incorrect as meiosis and apoptosis are not part of the haploid cell cycle, and degradation is not a typical event in the cell cycle.

3. What process involves the movement of water molecules through a selectively permeable membrane?

• A. Diffusion
• B. Osmosis
• C. Active Transport
• D. Facilitated Diffusion

Correct answer: B

Rationale: Osmosis is the process specifically involving the movement of water molecules through a selectively permeable membrane, from an area of higher water concentration to an area of lower water concentration. This process helps balance concentrations on both sides of the membrane. Choice A, Diffusion, refers to the movement of particles from an area of higher concentration to an area of lower concentration, not specific to water. Choice C, Active Transport, requires energy to move substances against their concentration gradient, unlike osmosis. Choice D, Facilitated Diffusion, involves the use of transport proteins to move specific substances across membranes, not limited to water molecules.

4. Which of the following is not true about enzymes?

• A. They catalyze reactions
• B. They lower the activation energy needed
• C. They have an active site
• D. They are typically proteins

Correct answer: B

Rationale: Enzymes lower the activation energy needed for a reaction to occur, not raise it. By lowering the activation energy, enzymes facilitate reactions, making them occur more easily and rapidly. Choice A is correct as enzymes indeed catalyze reactions. Choice C is correct as enzymes have specific active sites where substrates bind. Choice D is correct as enzymes are commonly proteins, although some RNA molecules also exhibit catalytic properties.

5. What is the process by which cells divide to form two identical daughter cells?

• A. Mitosis
• B. Meiosis
• C. Binary Fission
• D. Cellular Division

Correct answer: A

Rationale: The correct answer is A, Mitosis. Mitosis is the process in which a cell divides to form two identical daughter cells. Choice B, Meiosis, is a type of cell division that results in four non-identical daughter cells with half the number of chromosomes. Choice C, Binary Fission, is a form of asexual reproduction used by prokaryotic organisms. Choice D, Cellular Division, is a general term that encompasses various processes of cell division, but specifically, mitosis refers to the division resulting in two identical daughter cells.

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