Nursing Elites

1. What type of chemical bond connects the oxygen and hydrogen atoms in a molecule of water?

• A. Static bond
• B. Aquatic bond
• C. Ionic bond
• D. Covalent bond

Correct answer: D

Rationale: The correct answer is D, Covalent bond. Covalent bonds are formed between oxygen and hydrogen atoms in a water molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom, sharing electrons to achieve a stable configuration. Static bond (choice A) and Aquatic bond (choice B) are not valid types of chemical bonds. Ionic bond (choice C) involves the transfer of electrons between atoms of different electronegativities, which is not the case between oxygen and hydrogen in a water molecule.

2. What is the function of the cell membrane?

• A. To protect the cell and control what enters and exits
• B. To store energy
• C. To produce proteins
• D. To synthesize lipids

Correct answer: A

Rationale: The cell membrane, also known as the plasma membrane, serves as a protective barrier for the cell, separating the internal environment of the cell from the external environment. It is selectively permeable, meaning it controls the passage of substances in and out of the cell. This regulation of what enters and exits the cell is crucial for maintaining the cell's internal environment and ensuring proper functioning. Options B, C, and D are incorrect because storing energy, producing proteins, and synthesizing lipids are functions carried out by other cellular structures such as mitochondria, ribosomes, and endoplasmic reticulum, respectively, not the cell membrane.

3. Which feedback loop inhibits the stimulus or the deviation from homeostasis?

• A. Negative feedback loop
• B. Positive feedback loop
• C. Inhibitory feedback loop
• D. Stimulating feedback loop

Correct answer: A

Rationale: The correct answer is A: Negative feedback loop. Negative feedback loops work to inhibit the stimulus or reduce the deviation from a set point, maintaining homeostasis by counteracting any changes from the norm. In this case, the negative feedback loop acts to minimize any deviation from the body's internal balance, ensuring stability and optimal functioning. Choice B, a positive feedback loop, amplifies the stimulus or deviation, moving systems away from homeostasis. Choice C, an inhibitory feedback loop, is not a commonly recognized term in the context of feedback mechanisms. Choice D, a stimulating feedback loop, is not a standard term and does not accurately describe a feedback loop's role in maintaining homeostasis.

4. What characteristic unites all organisms in the kingdom Animalia?

• A. Multicellularity and heterotrophy
• B. Unicellular nature
• C. Photosynthesis
• D. Cell walls made of chitin

Correct answer: A

Rationale: A) Multicellularity and heterotrophy: This is the correct answer because all organisms in the kingdom Animalia are multicellular (composed of multiple cells) and exhibit heterotrophy (obtain nutrients by consuming other organisms). B) Unicellular nature: This is incorrect because organisms in the kingdom Animalia are multicellular, not unicellular. C) Photosynthesis: This is incorrect because organisms in the kingdom Animalia do not perform photosynthesis; they are heterotrophs that obtain nutrients by consuming other organisms. D) Cell walls made of chitin: This is incorrect because organisms in the kingdom Animalia do not have cell walls made of chitin. Chitin is a structural polysaccharide found in the cell walls of fungi, not animals.

5. What macromolecules are formed from amino acids, and what are their roles?

• A. Lipids; store energy
• B. Carbohydrates; provide energy
• C. Proteins; perform various functions like catalysis, transport, and structural support
• D. Nucleic acids; store genetic information

Correct answer: C

Rationale: The correct answer is C. Proteins are macromolecules formed from amino acids and have diverse roles, such as serving as enzymes, transport molecules, and providing structural support. They are essential for catalysis, cellular communication, immune response, and many other functions in living organisms. Choices A, B, and D are incorrect. Lipids are not formed from amino acids but from fatty acids and glycerol, mainly serving as energy storage molecules. Carbohydrates are composed of sugars and provide energy to the body. Nucleic acids, like DNA and RNA, are made up of nucleotides and store genetic information in cells.

Similar Questions