Nursing Elites

1. Which of the following quantities do catalysts alter to control the rate of a chemical reaction?

• A. Substrate energy
• B. Activation energy
• C. Inhibitor energy
• D. Promoter energy

Correct answer: B

Rationale: The correct answer is B: Activation energy. Catalysts function by reducing the activation energy needed for a chemical reaction to proceed. By lowering the activation energy, catalysts facilitate the reaction without being consumed themselves. Substrate energy, inhibitors, and promoters are not directly altered by catalysts in the same way activation energy is. Substrate energy refers to the energy of the reactants, which is not altered by catalysts. Inhibitors increase the activation energy required for a reaction, while promoters enhance the effectiveness of a catalyst but do not represent a quantity altered by catalysts.

2. Which term describes the allele for green eyes?

• A. Dominant
• B. Recessive
• C. Homozygous
• D. Heterozygous

Correct answer: B

Rationale: The correct answer is 'B: Recessive.' In genetics, eye color is determined by multiple genes, with green eyes often being associated with a recessive allele. When an individual carries two copies of the recessive allele for green eyes, they will express this eye color. Dominant alleles are expressed over recessive alleles. Homozygous refers to having two identical alleles for a particular gene, and heterozygous refers to having two different alleles. In this context, the allele for green eyes is recessive, meaning it is expressed only when an individual carries two copies of this specific allele. Therefore, 'Recessive' is the most appropriate term to describe the allele for green eyes, making it the correct answer.

3. Which type of blood cell is primarily responsible for fighting infections?

• A. Red blood cell
• B. White blood cell
• C. Platelet
• D. Plasma

Correct answer: B

Rationale: The correct answer is B: White blood cell. White blood cells are the primary cells responsible for fighting infections and foreign invaders in the body. Red blood cells carry oxygen to tissues, platelets help in blood clotting to prevent excessive bleeding, and plasma is the liquid component of blood that carries cells and nutrients. White blood cells, also known as leukocytes, play a crucial role in the immune system by identifying and destroying pathogens, such as bacteria, viruses, and other harmful substances. Therefore, they are the key players in the body's defense against infections, making them the correct answer in this scenario. While red blood cells, platelets, and plasma have essential functions in the body, they are not primarily responsible for combating infections like white blood cells.

4. Which of the following statements is true regarding a supersaturated solution?

• A. It is unstable and tends to crystallize
• B. It contains more solute than it could dissolve
• C. It has a higher concentration than a saturated solution
• D. It is rarely encountered in everyday solutions

Correct answer: A

Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.

5. A student hypothesizes that higher sugar consumption negatively impacts test scores. To investigate this, the student recruits participants to consume varying amounts of sugar, wait for one hour, and then complete an aptitude test. The student will record both the amount of sugar consumed and the test scores to analyze the relationship. What is the best experimental approach?

• A. Conduct one round of testing where each participant consumes a different amount of sugar.
• B. Conduct two rounds of testing: In the first round, participants consume varying amounts of sugar; in the second round, they consume the same amount of sugar as they did in the first round.
• C. Conduct two rounds of testing: In the first round, participants consume varying amounts of sugar; in the second round, participants consume no sugar.
• D. Conduct one round of testing where all participants consume the same amount of sugar.

Correct answer: C

Rationale: Option C provides the most thorough experimental design by including a control group. In the first round, varying sugar intake levels help explore the relationship between sugar consumption and test scores. In the second round, by having participants consume no sugar, the student can compare results to observe any changes due to sugar intake. This approach enhances the validity of the findings by accounting for potential confounding factors and better identifying causal relationships. Choice A is not ideal as it lacks a control group and does not compare the impact of sugar consumption. Choice B does not explore the effects of sugar consumption adequately as it does not include a group without sugar. Choice D does not allow for comparison between different sugar consumption levels, limiting the ability to draw meaningful conclusions.

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