Crude herbal drugs must be examined for yeast-like fungi. What agar can ensure development of these microorganisms so that associating microflora will grow very slowly or won't grow at all?

Correct Answer: A

Rationale: The correct answer is A: Sabouraud's peptone agar. This agar is specifically designed for the isolation of yeast and molds due to its low pH and high sugar content, creating an environment conducive for their growth. Yeast-like fungi thrive in this selective medium, while inhibiting the growth of bacteria and other contaminants. Summary: - Sabouraud's peptone agar is ideal for cultivating yeast-like fungi. - Endo agar is used for isolation of gram-negative bacteria, not fungi. - Milk-salt agar is used for lactobacilli and streptococci, not fungi. - Meat infusion agar is a general-purpose medium for cultivation of a wide range of microorganisms, not specifically for yeast-like fungi.

Correct Answer: B

Rationale: The correct answer is B because live vaccines can potentially revert to a virulent form, although this is extremely rare. This is due to the live attenuated virus in the vaccine potentially mutating back to a more dangerous form. Live vaccines are designed to be weakened but there is a small risk of reversion. Therefore, statement B is not correct. A: This statement is correct as immunocompromised individuals may have adverse reactions to live vaccines due to their weakened immune system. C: This statement is correct as microbes with many serotypes can make it challenging to develop a vaccine that covers all variations. D: This statement is correct as side effects to vaccination, although usually mild and temporary, can occur in some individuals.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Filamentous spiral nucleocapsid is characteristic of Filoviridae, such as Ebola virus. 2. Linear unsegmented single strand (-) RNA is a key feature of Filoviridae genomes. 3. The lipid bilayer membrane of cellular origin is found in Filoviridae viruses. 4. Therefore, the correct answer is B (Filoviridae) due to the alignment of all three morphological features. Summary: - A (Picornaviridae): Has an icosahedral capsid, not filamentous spiral. - C (Orthomyxoviridae): Has a segmented genome, not linear unsegmented. - D (Togaviridae): Has a spherical capsid, not filamentous spiral.

Correct Answer: C

Rationale: The correct answer is C: Bacteriophages are viruses that infect bacteria. Firstly, bacteriophages are viruses, not white blood cells or bacteria. They specifically target and infect bacteria, not fungi. This is known as a bacteriophage cycle where the virus injects its genetic material into the bacterial cell to replicate and eventually lyse the cell. This process is specific to bacteria and distinguishes bacteriophages from other microorganisms. Therefore, the correct answer is C as it accurately describes the nature and function of bacteriophages.

Correct Answer: A

Rationale: The correct answer is A: Spores. The Ozheshko method is used to stain spores, which are resistant structures produced by certain bacterial species. By studying the smear of streptobacillus preparation under oil immersion, one can observe the presence of spores as distinct, oval bodies within the bacteria. Spores are important for bacterial survival in harsh conditions. Summary: B: Capsules are not typically stained using the Ozheshko method. Capsules are usually visualized using negative staining techniques. C: Flagella are not stained by the Ozheshko method. Flagella are visualized using special staining techniques like the flagella stain. D: Inclusions are not specifically stained by the Ozheshko method. Inclusions are often observed using techniques that highlight cellular structures or components.