Nursing Elites

1. What is the pH of a solution with a hydrogen ion concentration of \(1 \times 10^{-9}\) M?

• A. 5
• B. 7
• C. 9
• D. 11

Correct answer: c

Rationale: The pH is calculated as the negative logarithm (base 10) of the hydrogen ion concentration. In this case, \(-\log(1 \times 10^{-9}) = 9\).

2. Which macromolecule serves as the repository of genetic information in all living organisms?

• A. Ribonucleic acid (RNA)
• B. Deoxyribonucleic acid (DNA)
• C. Protein
• D. Carbohydrate

Correct answer: B

Rationale: Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

3. A study finds a link between increased screen time and lower academic performance. What additional information would be most helpful in interpreting this finding?

• A. The average socioeconomic status of the study participants.
• B. The specific types of screen activities participants engaged in.
• C. Whether the students had access to healthy meals and snacks.
• D. The participants' ages and grade levels.

Correct answer: B

Rationale: Knowing the specific types of screen activities participants engaged in would provide crucial context for interpreting the link between increased screen time and lower academic performance. For example, if the majority of screen time was spent on educational apps or programs, the impact on academic performance may differ compared to if the screen time was mostly spent on social media or gaming. Understanding the nature of screen activities can help determine the potential mechanisms behind the observed relationship.

4. Which type of cell has a nucleus but lacks membrane-bound organelles?

• A. Plant cell
• B. Prokaryotic cell
• C. Animal cell
• D. Fungal cell

Correct answer: B

Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus, known as the nucleoid, which contains genetic material but lacks a membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant and animal cells (options A and C) are eukaryotic cells that have a nucleus and membrane-bound organelles. Fungal cells (option D) are also eukaryotic cells with a nucleus and organelles. Understanding the difference between prokaryotic and eukaryotic cells is essential in biology to grasp the diversity of cell structure and function.

5. The body's first line of defense against pathogens includes:

• A. Phagocytes
• B. Antibodies
• C. Memory B cells
• D. T lymphocytes

Correct answer: A

Rationale: Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the body's innate immune response, which is the first line of defense against pathogens. Phagocytes engulf and digest foreign particles, such as bacteria and viruses, helping to prevent infection and disease. Antibodies (option B) are produced by B cells and are part of the adaptive immune response, not the first line of defense. Memory B cells (option C) are also part of the adaptive immune response and are involved in mounting a faster and stronger response upon re-exposure to a pathogen. T lymphocytes (option D) are another type of white blood cell involved in the adaptive immune response, specifically in cell-mediated immunity.

6. You design an experiment to test the effectiveness of a new fertilizer. Which of the following factors would be considered a dependent variable?

• A. The type of fertilizer used
• B. The size and age of the plants
• C. The amount of plant growth observed
• D. The cost of the fertilizer per unit

Correct answer: C

Rationale: The dependent variable is the factor that is being measured or observed in an experiment. In this case, the amount of plant growth observed is the variable that is being influenced by the independent variable, which is the type of fertilizer used. The size and age of the plants (option B) could potentially be controlled variables, while the type of fertilizer used (option A) is the independent variable being tested. The cost of the fertilizer per unit (option D) is not directly related to the plant growth being measured in this experiment.

Similar Questions