Nursing Elites

1. What is the feedback mechanism in the endocrine system that helps maintain hormone balance?

• A. Positive feedback, where a hormone stimulates its own release
• B. Negative feedback, where a hormone suppresses its own release
• C. Cascade effect, where one hormone triggers the release of another
• D. Dual hormone system, where two hormones work together

Correct answer: B

Rationale: In the endocrine system, negative feedback is the mechanism by which hormone levels are regulated. When hormone levels reach a certain threshold, they signal the body to stop producing more of that hormone, thus maintaining a balance. Negative feedback (option B) is the correct answer as it helps in preventing overproduction of hormones by suppressing their own release. Positive feedback (option A) would lead to an excessive production of hormones, disrupting the balance. The cascade effect (option C) involves one hormone triggering the release of another but does not directly regulate hormone levels. The dual hormone system (option D) refers to two hormones working together but does not specifically address the feedback mechanism for maintaining hormone balance.

2. What is an alteration in the normal gene sequence called?

• A. DNA mutation
• B. Gene migration
• C. Polygenic inheritance
• D. Incomplete dominance

Correct answer: A

Rationale: A DNA mutation is the correct term used to describe an alteration in the normal gene sequence. It refers to changes in the DNA sequence that can result in different traits or characteristics. Gene migration involves the movement of genes between populations, polygenic inheritance refers to the inheritance of traits controlled by multiple genes, and incomplete dominance is a pattern of inheritance where neither allele is dominant.

3. What effect does a catalyst have on a chemical reaction?

• A. It speeds up the reaction.
• B. It slows down the reaction.
• C. It makes a reaction go in reverse.
• D. It prevents a reaction from taking place.

Correct answer: A

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction to occur, lowering the activation energy needed for the reaction to proceed. As a result, more reactant molecules can overcome this energy barrier and participate in the reaction, leading to a faster overall reaction rate. This explanation contradicts choices B, C, and D as a catalyst does not slow down, reverse, or prevent a reaction; instead, it accelerates the reaction by facilitating a more efficient route for the reaction to take place. Therefore, the correct answer is that a catalyst speeds up the reaction.

4. What is the primary function of the large intestine?

• A. To digest food
• B. To absorb water and form feces
• C. To absorb proteins
• D. To regulate blood pressure

Correct answer: B

Rationale: The correct answer is B. The primary function of the large intestine is to absorb water from digested food and form feces for elimination. It does not primarily digest food, absorb proteins, or regulate blood pressure. Choice A is incorrect because the large intestine does not digest food but rather absorbs nutrients and water. Choice C is incorrect as the absorption of proteins primarily occurs in the small intestine. Choice D is incorrect as the regulation of blood pressure is not a primary function of the large intestine.

5. Which statement is true regarding the process of digestion?

• A. Digestion of starch begins in the mouth.
• B. Amylase is produced by the stomach to help break down food in the upper intestine.
• C. The di- and tri-saccharides produced in early digestion are absorbed through the intestinal wall.
• D. Proteases are responsible for breaking down starches.

Correct answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.

Similar Questions