Nursing Elites

1. In a phospholipid molecule, the head:

• A. Is hydrophilic
• B. Is hydrophobic
• C. Is on the inner side of the layer
• D. Both A and C

Correct answer: D

Rationale: The head of a phospholipid is hydrophilic (water-loving) and is located on the outer side of the lipid bilayer, interacting with water molecules. This arrangement positions the hydrophobic tails inward, away from water. Therefore, the correct answer is D. Choice A is incorrect because the head is hydrophilic, not hydrophobic. Choice B is incorrect as the head is on the outer side, not the inner side of the layer.

2. Where can epithelial tissue be found?

• A. Organ lining
• B. Heart muscle
• C. Tendons
• D. Spinal cord

Correct answer: A

Rationale: Epithelial tissue is primarily found lining the surfaces of organs, such as the skin and the linings of various internal organs like the digestive tract, respiratory tract, and blood vessels. It serves as a protective barrier and helps with absorption and secretion. Heart muscle is made up of cardiac muscle tissue, tendons are primarily composed of dense connective tissue, and the spinal cord is composed of nervous tissue, none of which are classified as epithelial tissue.

3. What molecule is primarily responsible for providing energy to the cell?

• A. ATP
• B. DNA
• C. ADP
• D. Glycogen

Correct answer: A

Rationale: Correct! ATP (Adenosine Triphosphate) is the main molecule that stores and provides energy for cellular activities. ATP is known as the energy currency of the cell, where energy released from the breakdown of nutrients is stored in the high-energy phosphate bonds of ATP. Choices B, C, and D are incorrect because DNA carries genetic information, ADP is the precursor of ATP, and glycogen is a polysaccharide used for energy storage, not direct energy provision.

4. If bacteria are placed in a strong solution of salt water, they will shrink as water moves out of the bacteria. What is this process called?

• A. Dehydration synthesis
• B. Hydrolysis
• C. Osmosis
• D. Isotonic transport

Correct answer: C

Rationale: Osmosis is the process by which water molecules move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. In this case, when bacteria are placed in a strong solution of salt water, the high concentration of solutes outside the bacteria causes water to move out of the bacteria, leading to shrinkage. This process is known as osmosis. Dehydration synthesis (Choice A) is a process where molecules combine by removing water. Hydrolysis (Choice B) is the breakdown of molecules by the addition of water. Isotonic transport (Choice D) does not accurately describe the specific movement of water in or out of bacterial cells in a hypertonic solution.

5. A cell from heart muscle would more than likely contain an unusually high proportion of which of the following?

• A. lysosomes
• B. mitochondria
• C. mRNA
• D. ribosomes

Correct answer: B

Rationale: A cell from heart muscle would more than likely contain an unusually high proportion of mitochondria because the heart muscle requires a significant amount of energy to function properly. Mitochondria are the powerhouse of the cell and are responsible for producing energy in the form of ATP through cellular respiration. Therefore, to meet the high energy demands of the heart muscle, it would need a higher concentration of mitochondria compared to other cell types. Choices A, C, and D are incorrect because while lysosomes, mRNA, and ribosomes are essential components of a cell, they do not play as direct a role in meeting the high energy demands of heart muscle as mitochondria do.

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