Nursing Elites

1. What is the process in which RNA polymerase copies DNA into RNA, with DNA unwinding and serving as a template while RNA is assembled?

• A. Replication
• B. Transcription
• C. Translation
• D. Duplication

Correct answer: B

Rationale: The correct answer is B: Transcription. Transcription is the process where RNA polymerase reads the DNA template strand and synthesizes RNA, following the base-pairing rules. During transcription, DNA unwinds and serves as a template for the assembly of complementary RNA molecules. Replication (Choice A) is the process of making an identical copy of DNA, not RNA from DNA. Translation (Choice C) is the process of synthesizing proteins from mRNA. Duplication (Choice D) is a general term and does not specifically refer to the process described in the question.

2. Epithelial tissue, which covers surfaces, is further classified based on the number of cell layers. Simple epithelium has:

• A. No layers
• B. One layer
• C. Two to several layers
• D. Many tightly packed layers

Correct answer: B

Rationale: Simple epithelium consists of a single layer of cells. This type of epithelium is found in areas where absorption, secretion, and filtration occur, as it allows for efficient exchange of substances across the epithelial barrier. Simple epithelium is well-suited for diffusion and filtration processes due to its thin nature, enabling substances to pass through easily. Choice A, 'No layers,' is incorrect as epithelial tissue always consists of at least one cell layer. Choice C, 'Two to several layers,' describes stratified epithelium, not simple epithelium, which has only one layer. Choice D, 'Many tightly packed layers,' is more characteristic of stratified epithelium, where multiple layers of cells are present. Therefore, the correct answer is B: 'One layer.'

3. Which element's neutral atom has 2 electrons in the first shell and 6 electrons in the second shell of the electron cloud?

• A. Beryllium
• B. Carbon
• C. Helium
• D. Oxygen

Correct answer: D

Rationale: The correct answer is Oxygen. Oxygen has a total of 8 electrons, with 2 in the first shell and 6 in the second shell. This configuration matches the description provided in the question. Choice A, Beryllium, has 2 electrons in total, so it cannot have 2 in the first shell and 6 in the second. Choice B, Carbon, has 6 electrons in total, so it also does not match the given electron distribution. Choice C, Helium, has only 2 electrons in total and therefore does not fit the electron configuration described in the question.

4. In the electron cloud model, electrons occupy specific energy levels around the nucleus with varying probabilities. This model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.

• A. 2 protons and 6 neutrons
• B. 2 filled s orbitals and 6 filled p orbitals
• C. 2s orbitals with 2 and 6 electrons, respectively
• D. 4 filled electron shells

Correct answer: C

Rationale: The electron cloud model describes electrons existing in distinct energy levels, not fixed orbits. Option C correctly describes the electron configuration of an atom with 2s orbitals containing 2 electrons and 6 electrons in the 2p orbitals. This configuration aligns with the electron cloud model where electrons are found in specific energy levels with varying probabilities. Options A, B, and D do not accurately represent the electron cloud model.

5. Which hormone, produced by the pancreas, is released in response to low blood sugar levels and stimulates the release of glucose into the bloodstream?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Thyroxine

Correct answer: B

Rationale: Glucagon is the hormone produced by the pancreas that is released in response to low blood sugar levels. It acts to stimulate the release of glucose into the bloodstream by promoting the breakdown of glycogen in the liver. Insulin, conversely, is released in response to high blood sugar levels and promotes the uptake of glucose by cells. Cortisol is a steroid hormone produced by the adrenal glands that regulates metabolism and the immune response. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism but is not involved in responding to low blood sugar levels.

Similar Questions