Nursing Elites

1. Which type of bond involves the complete transfer of electrons between atoms?

• A. Covalent bond
• B. Ionic bond
• C. Metallic bond
• D. Hydrogen bond

Correct answer: B

Rationale: The correct answer is B, Ionic bond. Ionic bond involves the complete transfer of electrons from one atom to another, resulting in the formation of cations and anions. This transfer leads to the creation of strong electrostatic attraction between the oppositely charged ions. Covalent bonds, on the other hand, involve the sharing of electrons between atoms to achieve stability. Metallic bonds are formed in metals, where a sea of delocalized electrons surrounds positively charged metal ions, contributing to the metal's properties. Hydrogen bonds are intermolecular forces that occur between a hydrogen atom and a highly electronegative atom like oxygen or nitrogen, not involving the complete transfer of electrons.

2. Which of the following describes the path through which air moves during inhalation?

• A. mouth/nose > pharynx > larynx > trachea > bronchi > bronchioles > alveoli
• B. bronchioles > alveoli > bronchi > larynx > pharynx > lungs
• C. mouth/nose > bronchi > bronchioles > alveoli > lungs > trachea
• D. alveoli > bronchioles > lungs > bronchi > trachea > larynx > pharynx > mouth/nose

Correct answer: A

Rationale: The correct path through which air moves during inhalation is from the mouth/nose > pharynx > larynx > trachea > bronchi > bronchioles > alveoli. This sequence accurately represents the typical route air takes as it travels from the external environment into the lungs to facilitate gas exchange in the alveoli. Choice B is incorrect as it reverses the order of bronchioles and alveoli. Choice C is incorrect as it starts with mouth/nose but then incorrectly lists lungs before trachea. Choice D is incorrect as it reverses the entire sequence of the respiratory pathway, starting with alveoli instead of mouth/nose.

3. What is the role of enzymes in the body?

• A. To transport oxygen
• B. To speed up chemical reactions
• C. To regulate body temperature
• D. To store energy

Correct answer: B

Rationale: Enzymes act as biological catalysts that speed up chemical reactions in the body. They lower the activation energy required for reactions to occur, thus facilitating processes like digestion, metabolism, and other essential functions. Choice A is incorrect as the transportation of oxygen is primarily carried out by red blood cells. Choice C is incorrect as the regulation of body temperature involves mechanisms such as sweating and shivering. Choice D is incorrect as energy storage is mainly performed by molecules like glycogen and triglycerides.

4. Which structure allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.

5. What is the function of a cell wall?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store genetic material

Correct answer: A

Rationale: The cell wall is a rigid layer that surrounds the cell membrane in plant cells, fungi, and some bacteria. Its main function is to provide structural support and protection for the cell, helping maintain the cell's shape and preventing it from bursting or collapsing. The cell wall also allows for the passage of water, ions, and other molecules in and out of the cell. Options B, C, and D are incorrect because those functions are typically carried out by other cellular structures. Option B is performed by the cell membrane, option C by ribosomes, and option D by the nucleus, which stores genetic material.

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