Nursing Elites

1. What type of molecule forms the cell membrane and controls what enters and exits the cell?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleic acids

Correct answer: C

Rationale: The correct answer is C: Lipids. The cell membrane is primarily composed of a double layer of lipids called phospholipids. These phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails, which arrange themselves to form a barrier that controls the passage of substances in and out of the cell. While proteins are also present in the cell membrane and play important roles in transport and cell signaling, lipids are the main structural component responsible for the selective permeability of the membrane. Carbohydrates are typically found on the outer surface of the membrane and are involved in cell recognition and communication. Nucleic acids are not a major component of the cell membrane; they are primarily responsible for storing and transmitting genetic information within the cell.

2. The term "bioaccumulate" refers to...

• A. The natural decomposition of organic materials.
• B. The buildup of a substance in living organisms.
• C. The contamination of seawater with chemical pollutants.
• D. The physical entanglement of animals with plastic debris.

Correct answer: B

Rationale: The passage describes microplastics entering food chains and accumulating in organisms, aligning with bioaccumulation.

3. Which element is used in jewelry due to its malleability and resistance to tarnish?

• A. Iron
• B. Copper
• C. Gold
• D. Silver

Correct answer: C

Rationale: Gold's properties make it ideal for crafting durable and aesthetically pleasing jewelry

4. In nuclear transmutation, a target nucleus is bombarded with a particle to create:

• A. A heavier isotope of the same element
• B. A lighter isotope of the same element
• C. An entirely new element
• D. A chain reaction of nuclear fission

Correct answer: C

Rationale: In nuclear transmutation, a target nucleus is bombarded with a particle to create an entirely new element. During this process, the target nucleus absorbs the incoming particle, resulting in changes to its atomic number and sometimes its mass number. These changes can lead to the creation of a different element altogether. This is a fundamental concept in nuclear chemistry and is used in various applications, including the creation of new isotopes for research or medical purposes. Options A and B are incorrect because transmutation involves creating a different element, not just a heavier or lighter isotope of the same element. Option D, a chain reaction of nuclear fission, is also incorrect as it refers to a different process where a nucleus splits into smaller fragments, releasing energy and more neutrons to sustain the chain reaction.

5. What is the function of introns in eukaryotic genes?

• A. They code for protein sequences.
• B. They are involved in gene regulation.
• C. They are removed during mRNA processing.
• D. They are non-functional remnants of ancient DNA.

Correct answer: C

Rationale: Rationale: A) Introns do not code for protein sequences. Exons are the segments of DNA that code for proteins. B) While introns can indirectly influence gene regulation, their primary function is not directly involved in gene regulation. C) Introns are non-coding regions of DNA that are transcribed into pre-mRNA but are removed during mRNA processing through a process called splicing. This allows only the exons to be included in the mature mRNA that will be translated into proteins. D) While introns were once thought to be non-functional remnants of ancient DNA, research has shown that they can have regulatory functions and play a role in gene expression.

6. What is the outermost layer of the dermis, rich in collagen and elastin fibers that provide elasticity to the skin?

• A. Papillary layer
• B. Reticular layer
• C. Stratum basale
• D. Stratum corneum

Correct answer: A

Rationale: The correct answer is A: Papillary layer. The papillary layer is the outermost layer of the dermis and is rich in collagen and elastin fibers. These fibers provide elasticity to the skin, helping it maintain its structure and flexibility. The reticular layer, although deeper in the dermis, is not the outermost layer and is primarily responsible for providing strength and support to the skin. The stratum basale and stratum corneum are layers of the epidermis, not the dermis. The stratum basale is the deepest layer of the epidermis where new skin cells are formed, while the stratum corneum is the outermost layer of the epidermis composed of dead skin cells. Understanding the different layers of the skin is essential for comprehending its functions and properties.

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