The mold responsible for the production of penicillin belongs to the subgroup of:

Correct Answer: B

Rationale: The correct answer is B: Ascomycota. Penicillin is produced by the mold Penicillium, which belongs to the phylum Ascomycota. Ascomycota is known for its sac-like structures called asci that contain ascospores. Penicillium produces penicillin as a defense mechanism against bacteria. Basidiomycota (A) are known for producing mushrooms, Zygomycota (C) includes bread molds like Rhizopus, and Deuteromycota (D) is a classification for fungi with no known sexual reproductive stage.

Correct Answer: D

Rationale: The correct answer is D: amensalism. Penicillin mold produces a substance that inhibits the growth of bacteria, but it does not benefit nor harm the bacteria directly. This relationship is characterized by one organism (the mold) negatively affecting another (the bacteria) without any benefit or harm to itself. In parasitism (A), one organism benefits at the expense of another. In mutualism (B), both organisms benefit from the relationship. In commensalism (C), one organism benefits while the other is unaffected. Therefore, the mold producing penicillin fits the definition of amensalism.

Correct Answer: C

Rationale: The correct answer is C: Streptococcus pyogenes. This bacterium is commonly known as "flesh-eating bacteria" due to its ability to cause severe tissue destruction and necrotizing fasciitis. Streptococcus pyogenes produces toxins that break down skin and muscle tissues. Staphylococcus aureus (A) can cause skin infections but is not typically associated with necrotizing fasciitis. Staphylococcus epidermidis (B) is a normal skin flora and rarely causes infections. Propionibacterium acnes (D) is associated with acne and not known for causing tissue destruction. Therefore, the correct choice is Streptococcus pyogenes due to its unique ability to cause severe tissue damage and necrotizing fasciitis.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Aspergillus flavus is a fungus known to produce aflatoxin. 2. Aflatoxin is a potent carcinogen found in contaminated food. 3. Candida albicans is a yeast species not associated with aflatoxin production. 4. Claviceps purpurea is a fungus that produces ergot alkaloids, not aflatoxin. 5. Staphylococcus aureus is a bacterium known for causing food poisoning, not aflatoxin production. Summary: Aspergillus flavus is the correct answer as it is the organism known to produce aflatoxin, a carcinogenic substance. Other choices are incorrect as they are not associated with aflatoxin production.

Correct Answer: C

Rationale: The correct answer is C: Plague. Yersinia pestis is the bacterium responsible for causing the bubonic, septicemic, and pneumonic plague. The bacterium is transmitted to humans through infected flea bites or handling infected animals. Tonsillitis (A) is commonly caused by streptococcal bacteria, leprosy (B) is caused by Mycobacterium leprae, and rat fever (D) is another term for leptospirosis, caused by Leptospira bacteria.