Nokea
Which of the following bacteria are individuals with complement deficiencies more susceptible to?
- A. Escherichia coli
- B. Haemophilus influenzae
- C. Staphylococcus aureus
- D. Mycobacterium tuberculosis
Correct Answer: B
Rationale: Individuals with complement deficiencies are more susceptible to encapsulated bacteria. Haemophilus influenzae is an encapsulated bacterium, making it the correct choice. The complement system plays a crucial role in opsonization and killing of encapsulated bacteria. Escherichia coli (choice A) is not an encapsulated bacterium, so complement deficiency doesn't significantly increase susceptibility. Staphylococcus aureus (choice C) and Mycobacterium tuberculosis (choice D) are also not encapsulated bacteria, therefore complement deficiencies do not have a direct impact on susceptibility to these pathogens.
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What are the recommended measures to prevent the transmission of health care–associated infections (HAIs) (select all that apply)?
- A. Empty bedpans as soon as possible
- B. Use personal protective equipment
- C. Hand washing or alcohol-based sanitizing
- D. Have patients wear sandals in the shower
Correct Answer: B
Rationale: The correct answer includes options B and C. Using personal protective equipment and practicing proper hand hygiene are critical measures to prevent HAIs. Emptying bedpans promptly and having patients wear sandals in the shower are not directly related to preventing HAIs.
What is the correct order of steps needed for 2nd generation sequencing?
- A. DNA fragmentation, DNA isolation, amplification, primer ligation, sequencing
- B. Amplification, primer ligation, sequencing, DNA fragmentation, DNA isolation
- C. DNA isolation, DNA fragmentation, primer ligation, amplification, sequencing
- D. Sequencing, DNA isolation, DNA fragmentation, primer ligation, amplification
Correct Answer: C
Rationale: The correct order of steps for 2nd generation sequencing is C: DNA isolation, DNA fragmentation, primer ligation, amplification, sequencing. Firstly, DNA isolation is crucial to extract the DNA from the sample. Next, DNA fragmentation breaks the DNA into smaller fragments for sequencing. Primer ligation involves attaching primers to the DNA fragments. Amplification is necessary to make multiple copies of the DNA fragments for sequencing. Finally, sequencing is the process of determining the nucleotide sequence of the DNA fragments. This order ensures that the DNA is properly prepared and amplified before sequencing, leading to accurate results.
Choices A, B, and D are incorrect because they do not follow the correct sequence of steps required for 2nd generation sequencing. Incorrect sequences may lead to errors in the sequencing process and inaccurate results.
What is the medical term for excessive bleeding?
- A. Thrombosis
- B. Embolus
- C. Hemorrhage
- D. Hemostasis
Correct Answer: C
Rationale: The correct answer is C: Hemorrhage. Hemorrhage refers to excessive bleeding. Thrombosis (A) is the formation of blood clots, not excessive bleeding. Embolus (B) is a blood clot that travels through the bloodstream and blocks a blood vessel. Hemostasis (D) is the process of stopping bleeding, not the term for excessive bleeding. In summary, only choice C directly relates to the medical term for excessive bleeding.
The major role of the complement system is to work in conjunction with
- A. antibodies to lyse cells via the C8 and C9 components
- B. the major histocompatibility complex for cell recognition
- C. antibodies to opsonize cells
- D. the T-cell receptor for production of lymphokines
Correct Answer: A
Rationale: Rationale: The complement system is a group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens. Choice A is correct because the C8 and C9 components of the complement system form the membrane attack complex which lyses cells. Choices B, C, and D are incorrect because the complement system primarily functions independently of the major histocompatibility complex, antibodies for opsonization, and T-cell receptor for lymphokine production.
Avian Influenza has not so far caused a human pandemic because
- A. Avian flu causes only mild infection in humans compared to birds
- B. Avian flu recognizes a variant of sialic acid found only on avian cells
- C. Avian flu recognizes a variant of sialic acid only found deep in the lung tissue of humans, not in the upper airways
- D. H5N1 is included in the composition of the annual trivalent inactivated vaccine
Correct Answer: C
Rationale: The correct answer is C because avian flu recognizing a variant of sialic acid only found deep in the lung tissue of humans, not in the upper airways explains why it has not caused a human pandemic. This specificity limits human-to-human transmission as the virus cannot efficiently attach in the upper airways where respiratory droplets are expelled. Choices A and B are incorrect because avian flu can cause severe infections in humans and recognizes a variant of sialic acid found in both birds and humans, not just avian cells. Choice D is incorrect as the presence of H5N1 in the annual trivalent vaccine does not prevent human pandemic potential.