Fungal Diseases

Q40. A chronic infection is caused by a eukaryote with a chitinous cell wall that produces spores. Which organism is implicated?

[RRB Group D | 2026 | PYQ (2025 recruitment cycle)]

1. Fungus
2. Alga
3. Bacterium
4. Protozoan

Answer: (A) Fungus

Explanation: Fungi possess a true nucleus and cell walls containing chitin. Many reproduce by spores and some cause persistent infections in humans. Bacteria lack a true nucleus; protozoa usually lack a rigid chitin wall, making fungus the appropriate identification.

Q39. A fungal culture grows best in a warm, moist incubator. Which biological process is most directly favoured?

[RRB Group D | 2026 | PYQ (2025 recruitment cycle)]

1. Spore germination and fungal growth
2. Production of chlorophyll
3. Formation of red blood cells
4. Photosynthesis

Answer: (A) Spore germination and fungal growth

Explanation: Warmth and adequate moisture promote the germination of many fungal spores and the extension of hyphae. Humid skin folds similarly favour superficial fungal infections. Temperature requirements differ between species, and excessive heat can inhibit growth or kill fungi.

Q38. Rice blast is classified as which type of plant disease?

[CGPSC Prelims | 2025 | PYQ]

1. Fungal
2. Bacterial
3. Nutritional deficiency
4. Viral

Answer: (A) Fungal

Explanation: Rice blast is primarily caused by Magnaporthe oryzae, also called Pyricularia oryzae in its asexual form. The fungus infects leaves, nodes and panicles, producing characteristic lesions. Resistant varieties and appropriate disease management reduce crop damage.

Q37. Why do fungal spores help fungi survive and disperse under unfavourable conditions?

[MP Police Constable | 2025 | PYQ]

1. They always contain chlorophyll
2. They must fertilise an egg
3. They are relatively resistant and easily dispersed
4. They are always large and immobile

Answer: (C) They are relatively resistant and easily dispersed

Explanation: Fungal spores often have protective walls and can remain viable during unfavourable conditions. Their small size assists transport by air or contact. When moisture, nutrients and temperature become suitable, surviving spores germinate and establish new colonies.

Q36. Which fungal pathogen has been reported to develop resistance to azole antifungals through chromosomal changes?

[RRB Group D | 2025 | PYQ]

1. Candida albicans
2. Candida tropicalis
3. Aspergillus niger
4. Rhizopus stolonifer

Answer: (B) Candida tropicalis

Explanation: Candida tropicalis can acquire resistance-associated chromosomal alterations, including copy-number changes, alongside other mechanisms. Azole drugs such as fluconazole inhibit fungal ergosterol synthesis. Antifungal resistance requires laboratory surveillance because different Candida species may respond differently to treatment.

Q35. Which is NOT a principal criterion traditionally used to classify fungi into major groups?

[NEET | 2024 | PYQ]

1. Morphology of mycelium
2. Mode of nutrition
3. Mode of spore formation
4. Nature of fruiting body

Answer: (B) Mode of nutrition

Explanation: Traditional fungal classification considers the structure of mycelium, production of spores and fruiting bodies. Mode of nutrition is not the chief basis for these classes because many fungi share absorptive heterotrophy while differing substantially in reproduction.

Q34. Claviceps fusiformis causes which disease of pearl millet (bajra)?

[CCI Junior Assistant | 2024 | PYQ]

1. Ergot
2. Smut
3. Rice blast
4. Bacterial blight

Answer: (A) Ergot

Explanation: Claviceps fusiformis infects flowers of pearl millet and causes ergot disease. A sticky honeydew stage may be followed by dark fungal sclerotia replacing grains. Contaminated produce may contain toxic ergot alkaloids harmful to animals and humans.

Q33. Which plant-pathogenic fungus associated with silver-leaf disease has also been reported in a rare human infection?

[TNPSC Group 4 | 2024 | PYQ]

1. Plasmodiophora brassicae
2. Chondrostereum purpureum
3. Puccinia graminis
4. Taphrina deformans

Answer: (B) Chondrostereum purpureum

Explanation: Chondrostereum purpureum is best known as the cause of silver-leaf disease in certain trees. A rare human infection was reported, illustrating that fungal host ranges can occasionally surprise researchers. Such cases do not imply routine person-to-person transmission.

Q32. Which of these diseases is caused by a fungus?

[SSC CHSL Tier I | 2023 | PYQ (2022 recruitment cycle)]

1. COVID-19
2. Ringworm
3. Tuberculosis
4. Cholera

Answer: (B) Ringworm

Explanation: Ringworm, or dermatophytosis, is caused by dermatophyte fungi rather than worms. It commonly presents as an itchy, scaly patch. COVID-19 is viral, while tuberculosis and cholera are bacterial, making ringworm the only fungal option.

Q31. Assertion: Ringworm is a fungal disease.
Reason: It can be caused by Trichophyton and Microsporum.

Choose the correct response.

[MP Police Constable | 2023 | PYQ]

1. Both assertion and reason are correct
2. Only assertion is correct
3. Only reason is correct
4. Both are incorrect

Answer: (A) Both assertion and reason are correct

Explanation: The assertion and reason are both correct. Trichophyton and Microsporum are important dermatophyte genera causing infections of keratin-rich tissues. Epidermophyton is another recognized genus. These infections are termed tinea or dermatophytosis according to the affected body site.

Q30. Which type of organism is the causative agent of ergot disease in cereal crops?

[MP Forest Guard | 2023 | PYQ]

1. Virus
2. Bacterium
3. Nutritional factor
4. 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]

1. Fungus, bacterium, virus
2. Bacterium, fungus, virus
3. Virus, fungus, bacterium
4. 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]

1. Viruses
2. Bacteria
3. Genetic defects
4. 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]

1. Only II
2. Neither I nor II
3. Only I
4. 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]

1. Puccinia graminis f. sp. tritici
2. Xanthomonas citri
3. Cercospora arachidicola
4. 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)]

1. Ringworm
2. Diarrhoea due to cholera
3. Smallpox
4. 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. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 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]

1. Virus
2. Fungus
3. Protozoan
4. 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]

1. Mycosis
2. Virosis
3. Bacteremia
4. 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]

1. Virus
2. Bacterium
3. Fungus
4. 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.

Q20. Athlete’s foot is a disease caused by which organism group?

[West Bengal Police SI | 2019 | PYQ]

1. Fungi
2. Protozoa
3. Bacteria
4. Nematodes

Answer: (A) Fungi

Explanation: Athlete’s foot is a common fungal infection involving the skin of the feet. Warm, damp shoes and communal wet floors encourage transmission or persistence. Dermatophytes digest keratin and often produce peeling, itching and fissuring between toes.

Q19. Which is a plant disease caused by fungi?

[NVS Lab Attendant | 2018 | PYQ]

1. Citrus canker
2. Yellow vein mosaic
3. Rust of wheat
4. Aster yellows

Answer: (C) Rust of wheat

Explanation: Rust of wheat is fungal and is linked to Puccinia species. Citrus canker is bacterial, yellow vein mosaic is viral and aster yellows is associated with phytoplasmas. Differentiating microbial causes is essential for selecting suitable crop-protection measures.

Q18. Tikka disease of groundnut is primarily caused by which fungal genus?

[UP LT Grade Teacher (Biology) | 2018 | PYQ]

1. Fusarium
2. Colletotrichum
3. Alternaria
4. Cercospora

Answer: (D) Cercospora

Explanation: Tikka disease refers to leaf spots of groundnut. The early leaf spot agent is Cercospora arachidicola; the late leaf spot fungus is now often called Nothopassalora personata. Spots may reduce green leaf area and crop yield.

Q17. Which of these fungal genera includes species that can cause human disease?

[MP Police Sub-Inspector | 2017 | PYQ]

1. Rhizopus only in bread-making
2. Puccinia, the wheat rust fungus
3. Aspergillus
4. Agaricus, the edible mushroom

Answer: (C) Aspergillus

Explanation: Aspergillus includes species responsible for allergic disease, aspergilloma and invasive aspergillosis. Infection risk is particularly high in people with substantial immune suppression or pre-existing lung cavities. Many Aspergillus species are environmentally widespread moulds.

Q16. Which statement about fungi is incorrect?

[NEET Phase 2 | 2016 | PYQ]

1. They may be unicellular or multicellular
2. They are eukaryotic
3. Every fungus has a purely cellulosic cell wall
4. They are heterotrophic

Answer: (C) Every fungus has a purely cellulosic cell wall

Explanation: Fungal cell walls characteristically contain chitin and glucans, not universally pure cellulose. Fungi are eukaryotic and derive nutrients from organic sources. Both single-celled yeasts and multicellular filamentous moulds belong to the fungal kingdom.

Q15. Who explained the annual recurrence of wheat-rust infections in the Indian plains?

[UP TGT Biology | 2016 | PYQ]

1. B. B. Mundkur
2. K. C. Mehta
3. R. S. Singh
4. E. J. Butler

Answer: (B) K. C. Mehta

Explanation: Plant pathologist K. C. Mehta investigated the seasonal recurrence of wheat rusts in India. His work highlighted the movement of inoculum from cooler regions into the plains. Understanding rust epidemiology supports forecasting and protection of wheat crops.

Q14. Which organism causes red rot disease of sugarcane?

[NBE Junior Assistant | 2015 | PYQ]

1. Phytophthora infestans
2. Alternaria alternata
3. Colletotrichum falcatum
4. Cercospora personata

Answer: (C) Colletotrichum falcatum

Explanation: Red rot of sugarcane is caused by the fungus Colletotrichum falcatum. Infected stalks may show reddish internal tissues with pale patches and develop a sour smell. Clean planting material, resistant cultivars and field sanitation help limit its spread.

Q13. Lichens that colonise bare rock during ecological succession are symbiotic associations of which organisms?

[UPSC CSE Prelims | 2014 | PYQ]

1. Algae and bacteria
2. Algae and fungi
3. Bacteria and fungi
4. Fungi and mosses

Answer: (B) Algae and fungi

Explanation: Most lichens consist of a fungal partner and a photosynthetic partner, usually an alga or cyanobacterium. Their ability to colonise exposed rock contributes to primary succession. Although usually beneficial, this association illustrates fungal ecology rather than a disease.

Q12. Which fungal infection primarily produces white, curd-like patches inside the mouth?

[UPSC CDS | 2013 | Exam-style practice, not verified PYQ]

1. Oral candidiasis
2. Malaria
3. Diphtheria
4. Measles

Answer: (A) Oral candidiasis

Explanation: Oral candidiasis, also called thrush, commonly involves overgrowth of Candida yeasts on oral mucosa. White plaques may appear on the tongue or cheeks. Recent antibiotics, dentures and weakened immunity can increase susceptibility to infection.

Q11. Tinea capitis is a dermatophyte infection of which body region?

[RRB NTPC | 2012 | Exam-style practice, not verified PYQ]

1. Scalp
2. Intestine
3. Liver
4. Kidney

Answer: (A) Scalp

Explanation: Tinea capitis is a fungal infection of scalp hair and surrounding skin, common in children. Dermatophytes such as Trichophyton and Microsporum may cause scaling, broken hairs or patchy hair loss. Treatment typically requires an oral antifungal prescribed by a clinician.

Q10. Which fungus is a major cause of invasive mucormycosis?

[WBCS | 2011 | Exam-style practice, not verified PYQ]

1. Rhizopus species
2. Lactobacillus species
3. Plasmodium species
4. Vibrio species

Answer: (A) Rhizopus species

Explanation: Mucormycosis is caused by moulds of the order Mucorales, including Rhizopus species. It can affect sinuses, lungs or other tissues and is an urgent medical condition. Uncontrolled diabetes and substantial immunosuppression are important risk factors.

Q9. Histoplasmosis is mainly acquired through which route?

[UPPCS | 2010 | Exam-style practice, not verified PYQ]

1. Inhalation of fungal spores
2. Mosquito bites
3. Eating undercooked fish
4. Inherited mutation

Answer: (A) Inhalation of fungal spores

Explanation: Histoplasmosis usually follows inhalation of airborne spores from Histoplasma fungi growing in contaminated soil or similar environments. Lungs are commonly affected, and disseminated disease can occur in susceptible people. It is not ordinarily spread between people.

Q8. Which fungal genus commonly causes wilt disease in many cultivated plants?

[RAS / RPSC | 2009 | Exam-style practice, not verified PYQ]

1. Fusarium
2. Salmonella
3. Rhizobium
4. Azotobacter

Answer: (A) Fusarium

Explanation: Certain Fusarium oxysporum lineages cause vascular wilt in crops such as tomato and banana. The pathogen colonises water-conducting tissues and may lead to yellowing and wilting. Resistant varieties and clean planting material are useful management strategies.

Q7. Which condition is a fungal infection of the groin region?

[SSC CHSL | 2008 | Exam-style practice, not verified PYQ]

1. Tinea cruris
2. Chickenpox
3. Typhoid
4. Scurvy

Answer: (A) Tinea cruris

Explanation: Tinea cruris, commonly called jock itch, is a superficial dermatophyte infection of the groin. It produces itchy, often well-defined rashes. Sweat, tight clothing and poor drying can favour infection. Suitable antifungals and hygiene help recovery.

Q6. Aspergillosis most commonly refers to disease associated with which organism?

[MPPSC | 2007 | Exam-style practice, not verified PYQ]

1. Aspergillus fungi
2. Influenza virus
3. Mycobacterium tuberculosis
4. Entamoeba histolytica

Answer: (A) Aspergillus fungi

Explanation: Aspergillosis includes several conditions linked to Aspergillus moulds, ranging from allergic airway disease to invasive infection. Most people inhale its environmental spores without becoming ill. Severe disease is more likely with impaired immunity or damaged lungs.

Q5. Which group of fungi causes dermatophytosis by feeding on keratin?

[UPSC NDA | 2006 | Exam-style practice, not verified PYQ]

1. Dermatophytes
2. Cyanobacteria
3. Amoebae
4. Mycoplasmas

Answer: (A) Dermatophytes

Explanation: Dermatophytes are specialised fungi capable of infecting keratinised tissues such as skin, nails and hair. Major genera include Trichophyton, Microsporum and Epidermophyton. Their infections are often named tinea followed by the affected anatomical site.

Q4. What is the common name for fungal infection of the nails?

[SSC CGL | 2005 | Exam-style practice, not verified PYQ]

1. Onychomycosis
2. Conjunctivitis
3. Otitis media
4. Nephritis

Answer: (A) Onychomycosis

Explanation: Onychomycosis is a fungal nail infection caused by dermatophytes, yeasts or other moulds. Nails may become thick, brittle or discoloured, although similar changes have other causes. Laboratory testing may be needed before prolonged antifungal therapy.

Q3. Which practice reduces the likelihood of athlete’s foot?

[RRB Group D | 2004 | Exam-style practice, not verified PYQ]

1. Keeping feet clean and dry
2. Sharing damp towels
3. Wearing wet socks all day
4. Walking barefoot in public showers

Answer: (A) Keeping feet clean and dry

Explanation: Drying the spaces between toes, changing damp socks and wearing footwear in shared shower areas can reduce exposure and create less favourable conditions for dermatophytes. Sharing towels or keeping footwear wet may encourage transmission or persistence.

Q2. Which fungus can cause cryptococcal meningitis?

[State PSC examinations | 2003 | Exam-style practice, not verified PYQ]

1. Cryptococcus neoformans
2. Penicillium chrysogenum
3. Saccharomyces cerevisiae
4. Agaricus bisporus

Answer: (A) Cryptococcus neoformans

Explanation: Cryptococcus neoformans is an encapsulated yeast that may infect the lungs and, in vulnerable people, spread to the central nervous system. Cryptococcal meningitis is particularly important in advanced immunosuppression and requires prompt medical assessment and treatment.

Q1. Which statement correctly describes ringworm?

[WBCS | 2002 | Exam-style practice, not verified PYQ]

1. It is caused by dermatophyte fungi
2. It is caused by a roundworm
3. It is caused by cholera bacteria
4. It is always transmitted by mosquitoes

Answer: (A) It is caused by dermatophyte fungi

Explanation: Despite its name, ringworm is not a worm infestation. It is a superficial fungal infection that may form circular, scaly lesions. Direct contact and contaminated items can spread it. The particular dermatophyte and affected site influence treatment.