Q30. Which type of organism is the causative agent of ergot disease in cereal crops?
[MP Forest Guard | 2023 | PYQ]
- Virus
- Bacterium
- Nutritional factor
- Fungus
Answer: (D) Fungus
Explanation: Ergot disease is caused by fungi of the genus Claviceps, including C. purpurea in rye. Infected grains may be replaced by dark sclerotia containing alkaloids. Eating contaminated grain can cause ergotism, a serious toxin-related illness.
Q29. Match correctly: citrus canker, wheat rust and yellow-vein mosaic of okra are caused by which agents respectively?
[KVS Primary Teacher | 2023 | PYQ]
- Fungus, bacterium, virus
- Bacterium, fungus, virus
- Virus, fungus, bacterium
- Bacterium, virus, fungus
Answer: (B) Bacterium, fungus, virus
Explanation: Citrus canker is caused by Xanthomonas bacteria. Wheat rust is caused by Puccinia fungi, whereas yellow-vein mosaic of okra involves plant viruses. Identifying the pathogen class is important because antibacterial agents cannot control fungal or viral plant diseases.
Q28. Athlete’s foot is caused by which category of microorganisms?
[SSC MTS | 2022 | PYQ]
- Viruses
- Bacteria
- Genetic defects
- Fungi
Answer: (D) Fungi
Explanation: Athlete’s foot, or tinea pedis, is a dermatophyte infection affecting the feet, particularly spaces between toes. It spreads through contaminated surfaces or direct contact. Keeping feet dry and using appropriate antifungal treatment helps manage the condition.
Q27. Consider the pairs:
(I) Citrus canker—virus;
(II) Wheat rust—fungus.
Which pair is correct?
[SSC CPO | 2022 | PYQ]
- Only II
- Neither I nor II
- Only I
- Both I and II
Answer: (A) Only II
Explanation: Only the second pair is correct. Wheat rust results from infection by Puccinia fungi. Citrus canker, however, is bacterial, commonly caused by Xanthomonas citri. Disease names alone can be misleading, so remembering their causal organisms is useful.
Q26. Which organism causes black or stem rust of wheat?
[MPSC Group B | 2022 | PYQ]
- Puccinia graminis f. sp. tritici
- Xanthomonas citri
- Cercospora arachidicola
- Ustilago maydis
Answer: (A) Puccinia graminis f. sp. tritici
Explanation: Black or stem rust of wheat is caused by Puccinia graminis f. sp. tritici, an obligate fungal pathogen. It produces rust-coloured pustules on stems and leaves. Brown leaf rust and yellow stripe rust are caused by different Puccinia taxa.
Q25. Which of the following is a fungal disease?
[SSC MTS | 2021 | PYQ (2020 recruitment cycle)]
- Ringworm
- Diarrhoea due to cholera
- Smallpox
- Polio
Answer: (A) Ringworm
Explanation: Ringworm is a dermatophyte fungal infection affecting the skin and sometimes hair or nails. Smallpox and polio are viral illnesses, while cholera-associated diarrhoea is bacterial. Characteristic itchy, scaly lesions help distinguish common superficial fungal infections.
Q24. Which of the following can be cultured on artificial or synthetic growth media:
1. bacteria,
2. fungi,
3. viruses?
[UPSC CSE Prelims | 2021 | PYQ]
- 1 and 2 only
- 2 and 3 only
- 1 and 3 only
- 1, 2 and 3
Answer: (A) 1 and 2 only
Explanation: Bacteria and fungi can grow on suitable non-living nutrient media; fungi are frequently cultured on Sabouraud dextrose agar. Viruses require living host cells to replicate and cannot multiply independently on ordinary synthetic culture media.
Q23. Rust of wheat is caused by which kind of pathogen?
[DFCCIL Junior Executive | 2021 | PYQ]
- Virus
- Fungus
- Protozoan
- Bacterium
Answer: (B) Fungus
Explanation: Wheat rust is a fungal disease caused by Puccinia species. Stem, leaf and stripe rust involve distinct rust pathogens and may spread through airborne spores. Resistant crop varieties and monitoring are important components of disease prevention.
Q22. Which medical term refers to a disease caused by a fungus?
[WBCS | 2020 | Exam-style practice, not verified PYQ]
- Mycosis
- Virosis
- Bacteremia
- Helminthiasis
Answer: (A) Mycosis
Explanation: Mycosis is the general term for a fungal disease. Mycoses range from superficial skin infections to severe invasive disease, especially in immunocompromised patients. The precise diagnosis depends on the fungal species, infected tissue and clinical findings.
Q21. What is the causative type of organism in ringworm infection?
[RRB Junior Engineer | 2019 | PYQ]
- Virus
- Bacterium
- Fungus
- Liverwort
Answer: (C) Fungus
Explanation: Ringworm is not due to an annelid or roundworm. It is a contagious dermatophyte infection caused by fungi such as Microsporum or Trichophyton. Contact with infected people, animals or objects can transmit its spores or fungal fragments.
