Nursing Elites

1. What is the role of RNA interference in silencing genes?

• A. Increases protein production
• B. Promotes gene mutation
• C. Inhibits the expression of specific genes
• D. Repairs damaged DNA

Correct answer: C

Rationale: RNA interference (RNAi) is a biological process that involves the silencing of gene expression by inhibiting the translation of mRNA or by degrading mRNA molecules. This mechanism plays a crucial role in regulating gene expression and can be used to selectively silence specific genes. By interfering with the expression of specific genes, RNAi can downregulate protein production from those genes. Therefore, option C, 'Inhibits the expression of specific genes,' is the correct role of RNA interference in silencing genes. Options A, B, and D are incorrect because RNA interference does not increase protein production, promote gene mutation, or repair damaged DNA; its primary function is to inhibit gene expression by degrading or interfering with mRNA.

2. Which term refers to the space where lymph flows through the body?

• A. Artery
• B. Lumen
• C. Interstitial space
• D. Vein

Correct answer: C

Rationale: The correct answer is C: Interstitial space. This term specifically refers to the area where lymph flows between tissues. Lymph does not flow through arteries (choice A) or veins (choice D) as these vessels carry blood. The term 'lumen' (choice B) refers to the inside space of a tubular structure, like a blood vessel, but it does not specifically denote the space where lymph flows through the body.

3. Which of the following is a cluster of capillaries that functions as the main filter of the blood entering the kidney?

• A. The Bowman's capsule
• B. The Loop of Henle
• C. The glomerulus
• D. The nephron

Correct answer: C

Rationale: The correct answer is C, the glomerulus. The glomerulus is a cluster of capillaries in the kidney responsible for filtering blood as it enters the nephron. It plays a crucial role in the initial stages of urine formation by filtering waste products and excess substances from the blood. Choice A, the Bowman's capsule, is incorrect as it surrounds the glomerulus and captures the filtrate. Choice B, the Loop of Henle, is incorrect as it is part of the nephron responsible for water reabsorption. Choice D, the nephron, is incorrect as it comprises the functional unit of the kidney and includes the glomerulus, Bowman's capsule, and other structures.

4. Which word in the passage shows that the plunger is depressed and air is pushed out at the same time?

• A. Out
• B. Continued
• C. As
• D. Causes

Correct answer: C

Rationale: The correct answer is 'C: As.' In the provided extract, the word 'As' is used to indicate the simultaneous action of depressing the plunger and pushing out the air. It establishes a connection between the two actions, showing that they occur together. Choice A, 'Out,' refers to the result of pushing the air out, not the action happening simultaneously. Choice B, 'Continued,' suggests a subsequent action rather than a simultaneous one. Choice D, 'Causes,' indicates a cause-and-effect relationship, not the action happening simultaneously like the word 'As' does.

5. According to the wave theory of light, the bright fringes observed in a double-slit experiment correspond to:

• A. Constructive interference
• B. Destructive interference
• C. Increased diffraction
• D. Total internal reflection

Correct answer: A

Rationale: In a double-slit experiment based on the wave theory of light, the bright fringes are the result of constructive interference. Constructive interference occurs when light waves from the two slits arrive at a point in phase, reinforcing each other and creating a bright fringe. This reinforcement leads to the constructive addition of the wave amplitudes, resulting in a bright spot on the screen. Destructive interference, which would result in dark fringes, occurs when waves are out of phase and cancel each other out. Increased diffraction and total internal reflection are not related to the formation of bright fringes in a double-slit experiment. Therefore, the correct answer is constructive interference.

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