Nokea
Lytic cycle of the bacteriophages differs from the lysogenic one by
- A. lysogenetic phages destroy the host cell when leaving the cell
- B. lytic phages do not destroy the host cell
- C. do not differ
- D. none of them
Correct Answer: A
Rationale: The correct answer is A because in the lytic cycle, the bacteriophage destroys the host cell upon release, whereas in the lysogenic cycle, the phage integrates its DNA into the host genome without killing the host immediately. This integration may lead to the destruction of the host cell at a later stage. Choice B is incorrect as lytic phages do destroy the host cell. Choice C is incorrect as the two cycles have distinct mechanisms. Choice D is incorrect as there are clear differences between the lytic and lysogenic cycles.
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What is the primary function of bacterial ribosomes?
- A. Synthesize proteins
- B. Generate ATP
- C. Produce DNA
- D. Synthesize lipids
Correct Answer: A
Rationale: The correct answer is A: Synthesize proteins. Bacterial ribosomes are responsible for translating mRNA into proteins through a process called translation. Ribosomes do not generate ATP (choice B), produce DNA (choice C), or synthesize lipids (choice D). These processes are carried out by other cellular components such as mitochondria for ATP production, DNA polymerase for DNA replication, and enzymes for lipid synthesis. The primary function of bacterial ribosomes is protein synthesis, making choice A the correct answer.
The colonies of the fungi that grow on solid media are called:
- A. Hyphae
- B. Mycelium
- C. Spore
- D. Columella
Correct Answer: B
Rationale: The correct answer is B: Mycelium. Mycelium refers to the network of branching filaments that form the main body of a fungus. When fungi grow on solid media, they develop a visible mass of mycelium. Hyphae (A) are the individual filaments that make up mycelium. Spores (C) are reproductive cells produced by fungi. Columella (D) refers to a specialized structure found in some fungi but is not related to the colonies grown on solid media. Therefore, the correct term for the colonies of fungi on solid media is mycelium.
Chemically an antigen may be:
- A. Lipid
- B. Protein
- C. Polysaccharide
- D. Any of these
Correct Answer: D
Rationale: The correct answer is D because antigens can be composed of lipids, proteins, or polysaccharides. Antigens are molecules that can elicit an immune response in the body. They can be diverse in their chemical composition, leading to the recognition and response by the immune system. Therefore, the correct choice is D as antigens can be any of these chemical components. Choices A, B, and C are incorrect because they each represent a possible chemical composition of antigens, but the flexibility of antigens to be made up of any of these components makes D the most accurate choice.
Parents with ill child came to the infectionist. They worked in one of the Asian countries for a long time. Child has eathy colored skin, loss of appetite, laxity, enlarged liver, spleen, peripheral glands. What protozoan illness can this child have?
- A. Amebiasis
- B. Balantidiasis
- C. Visceral leishmaniasis
- D. Lambliasis
Correct Answer: C
Rationale: The correct answer is C: Visceral leishmaniasis. This disease is caused by the protozoan parasite Leishmania, which is transmitted by sandfly bites. The symptoms described in the question, such as enlarged liver and spleen, peripheral gland enlargement, and eathy colored skin, are characteristic of visceral leishmaniasis. Amebiasis (choice A) typically presents with gastrointestinal symptoms, Balantidiasis (choice B) is caused by a different parasite and presents with dysentery, and Lambliasis (choice D) is caused by Giardia lamblia and presents with diarrhea.
Infectious disease' is:
- A. Clinical term
- B. A term expressing the possibility of developing certain symptoms in an infection
- C. A+B
- D. No correct answer
Correct Answer: C
Rationale: The correct answer is C because "Infectious disease" is a combination of both a clinical term (A) and a term expressing the possibility of developing certain symptoms in an infection (B). Infectious diseases are illnesses caused by pathogenic microorganisms, such as bacteria, viruses, parasites, or fungi, that can spread directly or indirectly from person to person. Therefore, the term encompasses both the clinical aspect of the disease and the potential symptoms that may manifest in an infected individual. Choices A and B alone do not fully capture the comprehensive definition of infectious disease, making C the correct answer. Choice D is incorrect as there is a correct answer in this case.