Nursing Elites

1. The sum of all chemical reactions that occur in an organism is:

• A. product
• B. respiration
• C. metabolism
• D. synthesis

Correct answer: C

Rationale: Metabolism is the sum of all chemical reactions that occur within an organism to maintain life. It involves all the processes that break down molecules to release energy (catabolism) and build new molecules to support growth and maintenance (anabolism). Respiration refers specifically to the process of generating energy from the breakdown of glucose molecules. Synthesis is the creation of complex molecules from simpler ones. Therefore, metabolism is the most comprehensive term that encompasses all these processes within an organism.

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. Which of the following is necessary for cell diffusion?

• A. water
• B. membrane
• C. ATP
• D. gradient

Correct answer: D

Rationale: The correct answer is 'gradient.' In cell diffusion, substances move from an area of high concentration to an area of low concentration, driven by the concentration gradient. This process does not require water, membrane, or ATP specifically. Water can aid in the movement of substances, but it is not necessary for diffusion itself. The membrane is involved in regulating diffusion but is not a requirement for the process. ATP is not directly involved in simple diffusion processes; instead, it is more related to active transport mechanisms. Therefore, the concentration gradient is essential for cell diffusion to occur.

4. Why is homeostasis necessary?

• A. It maintains temperature
• B. It maintains pH
• C. It maintains glucose levels
• D. All of the above

Correct answer: D

Rationale: Homeostasis is necessary because it ensures the maintenance of a stable, relatively constant internal environment. This includes regulating various factors such as temperature, pH levels, and glucose levels to support optimal bodily functions and overall health. Choices A, B, and C are all correct as they represent key aspects of homeostasis that contribute to maintaining the body's internal balance.

5. Which of the following is false?

• A. Animal cells use lysosomes to break down old cells
• B. Animal cells use chloroplasts to gain energy
• C. Plant cells have a cell wall to maintain structure
• D. All of the above are true

Correct answer: B

Rationale: The statement "B. Animal cells use chloroplasts to gain energy" is false. Chloroplasts are only present in plant cells and certain algae, where they are responsible for photosynthesis to generate energy from sunlight. Animal cells rely on other organelles, such as mitochondria, for energy production. Choice A is true because animal cells use lysosomes to break down old cells and cellular waste. Choice C is true as plant cells have a cell wall composed of cellulose that provides structural support and protection.

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