Q.42
ICAR AIEEA PG 2024 - Plant Sciences
MCQ (Single Correct) +4 −1
English हिन्दी

Which of the following is NOT a feature of Oomycetes plant pathogens?

निम्नलिखित में से कौन सा ऊमाईसीट्स (Oomycetes) पादप रोगजनकों का लक्षण नहीं है?

EXPLANATION Fungal Plant Pathogens: Classification, Spore Morphology, Life Cycles and Etiology

Distinguishing Characteristics of Oomycetes:

  • Oomycetes (water molds, downy mildews, Phytophthora, Pythium) belong to the kingdom Stramenopila / Chromista, distinct from true fungi (Eumycota).
  • Key Features of Oomycetes:
  • Coenocytic mycelium: Aseptate, multinucleate hyphae (with cell walls composed predominantly of $\beta$-glucans and cellulose, lacking chitin).
  • Hyaline mycelium and sporangia: Colorless, transparent structures.
  • Motile zoospores: Characteristic biflagellate heterokont zoospores bearing one forward-directed tinsel flagellum and one backward-directed whiplash flagellum.
  • They do NOT produce pigmented or coloured spores (such as melanized or dark spores found in Ascomycota/Basidiomycota like Alternaria or Puccinia).
Therefore, 'Coloured spores' is NOT a feature of Oomycetes. Correct Answer: Option 2 (Coloured spores).

विस्तृत व्याख्या:

Distinguishing Characteristics of Oomycetes (ऊमाईसीट्स के प्रमुख लक्षण):

  • Oomycetes (water molds, downy mildews, Phytophthora, Pythium) belong to the kingdom Stramenopila / Chromista, distinct from true fungi (Eumycota).
  • Key Features of Oomycetes:
  • Coenocytic mycelium: Aseptate, multinucleate hyphae (with cell walls composed predominantly of $\beta$-glucans and cellulose, lacking chitin).
  • Hyaline mycelium and sporangia: Colorless, transparent structures.
  • Motile zoospores: Characteristic biflagellate heterokont zoospores bearing one forward-directed tinsel flagellum and one backward-directed whiplash flagellum.
  • They do NOT produce pigmented or coloured spores (such as melanized or dark spores found in Ascomycota/Basidiomycota like Alternaria or Puccinia).
Therefore, 'Coloured spores' is NOT a feature of Oomycetes. Correct Answer: Option 2 (Coloured spores).
Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report
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