Nursing Elites

1. Which of the following structures in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The correct answer is B: Alveoli. The alveoli in the lungs are responsible for gas exchange. They have a thin membrane that allows for the exchange of oxygen and carbon dioxide between the air in the lungs and the blood in the capillaries surrounding them. This process is essential for respiration, providing oxygen to the body's tissues and removing carbon dioxide, a waste product of cellular metabolism. Choices A, C, and D are incorrect. The trachea is a passageway that carries air to and from the lungs but is not directly involved in gas exchange. Bronchi are airway passages that further divide into smaller bronchioles leading to the alveoli but do not perform gas exchange themselves. The diaphragm is a muscle involved in the breathing process by aiding in inhalation and exhalation, but it is not the structure responsible for gas exchange in the respiratory system.

2. How are sister chromatids distinguished from homologous chromosomes in meiosis I?

• A. Sister chromatids share the same centromere, while homologous chromosomes have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologous chromosomes have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologous chromosomes attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologous chromosomes separate during anaphase II.

Correct answer: B

Rationale: In meiosis I, sister chromatids are exact copies of each other, containing identical DNA sequences. On the other hand, homologous chromosomes are pairs of chromosomes, with one inherited from each parent, and they can have different versions of genes due to genetic recombination during crossing over in prophase I. Choice A is incorrect because homologous chromosomes naturally have different centromeres. Choice C is incorrect as sister chromatids and homologous chromosomes do not exhibit repulsion or attraction during synapsis. Choice D is incorrect as sister chromatids separate during anaphase II, not anaphase I, while homologous chromosomes separate during anaphase I.

3. To which section of the library should Jorgen go to learn more about the letters of the Greek alphabet and the meaning of the word 'beta'?

• A. 200
• B. 400
• C. 700
• D. 900

Correct answer: B

Rationale: Jorgen should go to section 400 in the library to learn more about the Greek alphabet and the meaning of the word 'beta'. Section 400 is dedicated to languages, which makes it the most appropriate place for this specific inquiry. Choices A, C, and D are incorrect because section 200 is dedicated to religion, section 700 covers arts and recreation, and section 900 focuses on history, geography, and biography, none of which would provide information about the Greek alphabet or the word 'beta'.

4. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

5. Mrs. Jones's class is conducting an experiment. They will substitute artificial sweetener for sugar in a cookie recipe to determine the effect on the overall color of the baked cookies. Which of the following should be included in the instructions for the experiment?

• A. When preparing the batch that includes artificial sweetener, 20% more water should be included.
• B. The bake temperature should be decreased from 425°F to 400°F.
• C. The batch with artificial sweetener should be baked on a stainless steel sheet.
• D. Ingredient proportions, bake time, bake temperature, and cookie sheet material should all be kept the same between the two batches.

Correct answer: D

Rationale: To ensure a valid comparison and isolate the impact of the artificial sweetener, the experiment should maintain consistency in all factors except the sugar substitution. By keeping ingredient proportions, bake time, bake temperature, and cookie sheet material the same, any observed differences in the color of the cookies can be attributed to the artificial sweetener rather than other variables. Choices A, B, and C introduce additional variables that could confound the results. Choice A would alter the consistency of the recipe by adjusting the water content, Choice B would introduce a change in baking temperature which could affect the outcome, and Choice C suggests a change in the type of baking sheet used, potentially impacting the baking process and results. Therefore, maintaining consistency in all other factors except for the sugar substitution is crucial for a reliable experiment.

Similar Questions