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. Why do high-salt content foods not require refrigeration to prevent spoilage?

• A. Osmosis
• B. Diffusion
• C. Active transport
• D. Passive transport

Correct answer: A

Rationale: Osmosis is the natural process that prevents high-salt content foods from spoiling without the need for refrigeration. Osmosis involves the movement of water across a semi-permeable membrane from an area of lower solute concentration (water) to an area of higher solute concentration (salt). In high-salt content foods, the salt acts as a preservative by drawing moisture out of bacteria or other microorganisms, making it difficult for them to survive and spoil the food. This process helps in preserving the food and preventing spoilage even without refrigeration. Choices B, C, and D are incorrect because they do not involve the specific mechanism of water movement in response to the salt concentration in high-salt content foods.

3. How is the plasma membrane arranged?

• A. In a single layer made of proteins
• B. In a double layer made of proteins
• C. In a single layer of phospholipids
• D. In a double layer of phospholipids

Correct answer: D

Rationale: The plasma membrane is arranged in a double layer of phospholipids, known as a phospholipid bilayer. This structure consists of two layers of phospholipid molecules with hydrophilic heads facing the exterior and hydrophobic tails facing the interior, providing a semipermeable barrier for the cell. Choice A is incorrect because the plasma membrane is not made of a single layer of proteins. Choice B is incorrect as the double layer is composed of phospholipids, not proteins. Choice C is incorrect as the plasma membrane is not made of a single layer of phospholipids but rather a double layer.

4. Which type of sugar is a disaccharide?

• A. Sucrose
• B. Fructose
• C. Glucose
• D. Galactose

Correct answer: A

Rationale: The correct answer is A, Sucrose. Sucrose is a disaccharide composed of one molecule of glucose and one molecule of fructose. When glucose and fructose combine, they form sucrose. Choice B, Fructose, is a monosaccharide, not a disaccharide. Choice C, Glucose, is also a monosaccharide, not a disaccharide. Choice D, Galactose, is another monosaccharide and not a disaccharide.

5. Which of the following is the structure of the male reproductive system that stores spermatozoa during the maturation process?

• A. vas deferens
• B. scrotum
• C. epididymis
• D. testicular artery

Correct answer: C

Rationale: The epididymis is the structure of the male reproductive system that stores spermatozoa during the maturation process. Sperm cells produced in the testes move to the epididymis, where they mature and become motile before being ejaculated. The vas deferens is responsible for transporting mature sperm to the urethra during ejaculation, the scrotum holds the testes and helps regulate their temperature for sperm production, and the testicular artery supplies blood to the testes. Therefore, choices A, B, and D are incorrect as they do not play a direct role in storing spermatozoa during the maturation process.

Similar Questions