Nursing Elites

1. 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.'

2. The number of protons in an atom determines its:

• A. Mass number
• B. Atomic number
• C. Atomic weight
• D. Valence electron count

Correct answer: B

Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.

3. The kidneys are bean-shaped organs that perform several vital functions. Which of the following is NOT a primary function of the kidneys?

• A. Filtering waste products from the blood
• B. Regulating blood pressure
• C. Producing red blood cells
• D. Maintaining water balance in the body

Correct answer: C

Rationale: The correct answer is C. The kidneys do not produce red blood cells. This function is carried out by the bone marrow. The primary functions of the kidneys include filtering waste products from the blood, regulating blood pressure, and maintaining water balance in the body. Red blood cells are produced in the bone marrow, not in the kidneys. Choices A, B, and D are incorrect as they are primary functions of the kidneys, which involve filtering waste products, regulating blood pressure, and maintaining water balance in the body, respectively.

4. Which organelle in the cell is responsible for protein synthesis?

• A. Ribosome
• B. Nucleus
• C. Mitochondrion
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A: Ribosome. Ribosomes are the organelles responsible for protein synthesis in the cell. They are the cellular machinery where translation, the process of assembling proteins from amino acids based on mRNA sequences, occurs. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum. The nucleus (choice B) houses DNA but is not directly involved in protein synthesis. Mitochondria (choice C) are responsible for energy production through cellular respiration, not protein synthesis. The Golgi apparatus (choice D) is involved in modifying, sorting, and packaging proteins for secretion, not in the synthesis of proteins.

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.

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