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. T cells in the immune system can be categorized into different types. What type of T cell directly kills infected body cells?

• A. Helper T cells
• B. Cytotoxic T cells
• C. Regulatory T cells
• D. Memory T cells

Correct answer: B

Rationale: Cytotoxic T cells directly kill infected body cells by recognizing specific antigens on the surface of infected cells and releasing cytotoxic substances to induce cell death, eliminating the infected cells. Helper T cells assist in coordinating the immune response, regulatory T cells help maintain immune tolerance, and memory T cells mount a faster and stronger response upon re-exposure to a previously encountered antigen. Therefore, the correct answer is cytotoxic T cells as they play a crucial role in directly targeting and destroying infected cells.

3. What is the cellular function of cilia and flagella?

• A. Cilia and flagella are responsible for cell movement.
• B. Cilia and flagella synthesize proteins.
• C. Cilia and flagella help protect the cell from its environment.
• D. Cilia and flagella have enzymes that help with digestion.

Correct answer: A

Rationale: The correct answer is A: Cilia and flagella are responsible for cell movement. Cilia and flagella are specialized structures found on the surface of many types of cells. They are involved in the movement of the cell itself or in moving substances around the cell. This movement helps in various functions such as propulsion, moving fluids, and sensing the environment. Choices B, C, and D are incorrect. Cilia and flagella are not involved in synthesizing proteins, protecting the cell from its environment, or aiding in digestion. Their primary function is related to cell movement and cellular transport.

4. Which of the following cell organelles is the site of lipid synthesis?

• A. smooth endoplasmic reticulum
• B. ribosome
• C. rough endoplasmic reticulum
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is the smooth endoplasmic reticulum. This organelle lacks ribosomes on its surface, unlike the rough endoplasmic reticulum, which is involved in protein synthesis. The enzymes present in the smooth endoplasmic reticulum are responsible for synthesizing lipids such as phospholipids and steroids. Choice B, ribosomes, are responsible for protein synthesis and not lipid synthesis. Choice C, rough endoplasmic reticulum, is involved in protein synthesis due to the presence of ribosomes. Choice D, Golgi apparatus, is responsible for modifying, sorting, and packaging proteins for secretion, not lipid synthesis.

5. Which skin condition is characterized by red, itchy, and inflamed patches?

• A. Eczema
• B. Psoriasis
• C. Melanoma
• D. Keloid

Correct answer: A

Rationale: Eczema is a skin condition characterized by red, itchy, and inflamed patches. It is a common condition that can vary in severity and often presents with symptoms such as dry, scaly skin, and sometimes oozing or crusting. Psoriasis, on the other hand, presents with red, scaly patches but is not typically described as itchy. Melanoma is a type of skin cancer characterized by the development of abnormal moles, while keloid is a type of raised scar that can occur after an injury to the skin. Therefore, the correct answer is eczema due to its specific symptom presentation of red, itchy, and inflamed patches.

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