Nokea
Identify the correct statement(s). In eukaryotic microorganisms:
- A. mRNA is short-lived (minutes).
- B. a single, circular chromosome is present.
- C. 5s, 16s, and 23s ribosomal RNA's are present.
- D. extrachromosomal DNA can be present.
Correct Answer: D
Rationale: The correct answer is D because extrachromosomal DNA, such as plasmids, can be present in eukaryotic microorganisms. This is true for certain organisms like yeast and some fungi. These DNA molecules are separate from the main chromosomal DNA and can carry additional genetic information.
A: mRNA in eukaryotic microorganisms is not short-lived; it can have varying lifespans depending on the specific mRNA molecule and cellular conditions.
B: Eukaryotic microorganisms typically have multiple linear chromosomes, not a single circular chromosome.
C: While 5s, 16s, and 23s ribosomal RNAs are present in prokaryotic organisms, eukaryotic microorganisms have different types of ribosomal RNA subunits.
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A patient prescribed corticosteroids for arthritis is surprised to learn of an immune disorder. What should the nurse explain as the reason for the patient not demonstrating typical signs of immune dysfunction?
- A. The arthritis is masking the normal immune response.
- B. The corticosteroids are causing the thymus gland to malfunction.
- C. The arthritis is interfering with the function of immunoglobulins.
- D. Corticosteroids are impacting normal immune response functioning.
Correct Answer: D
Rationale: The correct answer is D because corticosteroids are known to suppress the immune system by inhibiting the production of pro-inflammatory cytokines and preventing the activation of immune cells. This suppression can lead to a decreased immune response, making it less likely for the patient to exhibit typical signs of immune dysfunction.
A: The arthritis masking the immune response is not a plausible explanation as arthritis does not directly affect immune function.
B: Corticosteroids do not cause the thymus gland to malfunction; they mainly impact immune response at the cellular level.
C: Arthritis affecting immunoglobulin function is not a common mechanism of immune dysfunction in this context.
For which type of malignancy should the nurse expect the use of the intravesical route of regional chemotherapy delivery?
- A. Bladder
- B. Leukemia
- C. Osteogenic sarcoma
- D. Metastasis to the brain
Correct Answer: A
Rationale: Intravesical chemotherapy is used for bladder cancer to deliver drugs directly into the bladder.
How do cytokines typically function in the body?
- A. In an endocrine manner
- B. In an autocrine and paracrine manner
- C. Solely by direct contact with pathogens
- D. By degrading immune cells
Correct Answer: B
Rationale: The correct answer is B because cytokines primarily function in an autocrine and paracrine manner. Autocrine signaling occurs when a cell produces a cytokine that acts on the same cell, while paracrine signaling involves cytokines acting on nearby cells. This allows cytokines to regulate immune responses locally. Option A is incorrect as endocrine signaling involves hormones acting on distant target cells via the bloodstream, which is not the primary function of cytokines. Option C is incorrect because cytokines do not require direct contact with pathogens to function. Option D is incorrect as cytokines do not degrade immune cells but rather regulate immune responses.
The patient was told she has carcinoma in situ, and the student nurse wonders what that is. How should the nurse explain this to the student nurse?
- A. Evasion of the immune system by cancer cells
- B. Lesion with histologic features of cancer except invasion
- C. Capable of causing cellular alterations associated with cancer
- D. Tumor cell surface antigens that stimulate an immune response
Correct Answer: B
Rationale: Carcinoma in situ refers to a lesion with histologic features of cancer but without invasion into surrounding tissues.
Following class of restriction endonucleases is commercially available and used in recombinant DNA technology:
- A. Class 1
- B. Class 2
- C. Class 3
- D. Class 5
Correct Answer: B
Rationale: The correct answer is B: Class 2. Class 2 restriction endonucleases are commonly used in recombinant DNA technology due to their specificity for recognizing short DNA sequences and cleaving within or near these sequences. They are commercially available, easy to use, and have well-defined recognition sites, making them ideal for molecular cloning applications.
Choice A (Class 1) is incorrect because Class 1 enzymes require both ATP and S-adenosyl methionine for activity, making them less practical for routine laboratory use.
Choice C (Class 3) is incorrect because Class 3 enzymes cleave DNA at two sites, potentially leading to unwanted DNA fragmentation in recombinant DNA technology.
Choice D (Class 5) is incorrect because Class 5 restriction enzymes do not exist in the classification system of restriction endonucleases.