Nursing Elites

1. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: c

Rationale: Ductility is the property that describes a substance's ability to be stretched into thin wires without breaking.

2. What is the primary function of DNA polymerase?

• A. Packaging DNA
• B. Replicating DNA
• C. Transcribing DNA
• D. Translating mRNA

Correct answer: B

Rationale: Rationale: DNA polymerase is an enzyme responsible for synthesizing new DNA strands during DNA replication. It adds nucleotides to the growing DNA strand based on the template provided by the existing DNA strand. This process ensures that genetic information is accurately copied and passed on to daughter cells during cell division. Packaging DNA (option A) refers to the coiling and organization of DNA into chromatin, a process involving histones and other proteins. Transcribing DNA (option C) involves the synthesis of RNA from a DNA template, a process carried out by RNA polymerase. Translating mRNA (option D) refers to the process of protein synthesis where the information encoded in mRNA is used to assemble amino acids into a polypeptide chain.

3. A lab needs 200ml of a 5% salt solution. They only have a 10% solution. How much 10% solution and water should be mixed?

• A. 100ml 10% solution, 100ml water
• B. 150ml 10% solution, 50ml water
• C. 160ml 10% solution, 40ml water
• D. 200ml 10% solution, 0ml water

Correct answer: B

Rationale: Rationale: 1. Let x be the volume of the 10% solution needed and y be the volume of water needed. 2. The total volume of the final solution is 200ml, so x + y = 200. 3. The concentration of the final solution is 5%, so the amount of salt in the final solution is 0.05 * 200 = 10g. 4. The amount of salt in the 10% solution is 0.1x, and the amount of salt in the water is 0, so the total amount of salt in the final solution is 0.1x. 5. Since the total amount of salt in the final solution is 10g, we have 0.1x = 10. 6. Solving for x, we get x = 100ml. 7. Substituting x =

4. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

• A. The rate of mutation is constant across all genes and all species.
• B. Species with more morphological similarities diverged more recently.
• C. Mutations are always beneficial and contribute to increased fitness.
• D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

5. The fundamental units of structure and function in all living organisms, including humans, are termed:

• A. Muscles
• B. Organs
• C. Tissues
• D. Cells

Correct answer: D

Rationale: The correct answer is D: Cells. Cells are the fundamental units of structure and function in all living organisms, including humans. They are the building blocks of life, performing various functions necessary for an organism to survive and thrive. Muscles (A) are composed of muscle tissue, which is made up of muscle cells. Organs (B) are structures made up of different types of tissues working together. Tissues (C) are groups of cells that work together to perform specific functions within an organism. However, cells are the smallest unit of life and are responsible for carrying out all the essential processes needed for an organism to function.

6. The feedback loop is a crucial concept in endocrine regulation. In a negative feedback loop, high levels of a hormone can:

• A. Further stimulate the release of the same hormone
• B. Inhibit the release of the hormone or its production
• C. Have no effect on the hormone's regulation
• D. Increase the need for another hormone entirely

Correct answer: B

Rationale: In a negative feedback loop, high levels of a hormone signal the body to stop producing more of that hormone in order to maintain homeostasis. This is a self-regulating mechanism to prevent excessive levels of the hormone. Option B is correct because in this scenario, the high levels of the hormone will inhibit its further release or production. This feedback loop helps ensure that hormone levels stay within a narrow range, preventing overstimulation or imbalance in the endocrine system. Options A, C, and D are incorrect as they do not align with the concept of negative feedback regulation in endocrine systems.

Similar Questions