Competitive Exams: Botany MCQs (Practice-Test 30 of 104)

  1. Which one of the following statements is NOT correct?

    1. Pauling got Nobel Prize for discovering helical structure of proteins

    2. Genetic code is the outcome of experiments done by Khorana and Kornberg

    3. Fischer discovered presence of purine and pyrimidine bases in nucleic acids

    4. Archibald Garrod was the first to hint that genes operate through enzymes

  2. Holandric genes are located

    1. Both in X and Y chromosome

    2. Only in Y chromosome

    3. Only in X chromosome

    4. Only in autonomies

  3. The phenomena of coupling and repulsion was explained by

    1. Bateson and Punnett

    2. Beadle and Tatum

    3. Bridges

    4. Morgan

  4. In Neurospora, when a single crossing over occurs between two loci (Aa & Bb) in the tetrad stage after chromosomal replication, the frequency of recombinant products in ascosporic would be

    1. 25%

    2. 50%

    3. 75%

    4. 100%

  5. Unrelated alleles exhibiting their similar gene products fully are due to

    1. Pseudo-dominance

    2. Co-dominance

    3. Super dominance

    4. Hyper-dominance

  6. Which symbiotic relationship is NOT observed between Rhodium species and plants modulated?

    1. R. Meliloti: Trigonella foenumgracum

    2. R. Leguminosarum: Lens esculenta

    3. R. Japonicum: Glycine max

    4. R. Lupini: Cajanus cajan

  7. DNA is amplified by

    1. PCR technique

    2. Southern Blotting technique

    3. Northern Blotting technique

    4. Nucleic acid hybridization technique

  8. Which one of the following is NOT a component of lactose operon in bacteria?

    1. Operator

    2. Repressor

    3. Regulator

    4. Structural gene

  9. Which fusigenic agent below is required for cybrid production?

    1. Polyvinylpyrrolidine (PVP)

    2. Diethylene glycol succinate (DEGS)

    3. Polyethylene glycol (PEG)

    4. Dimethyl sulfoxide (DMSO)

  10. Which one of the following fungi is a biotroph?

    1. Puccinia

    2. Pythium

    3. CVollectorichum

    4. Fusarium

  11. Which one of the following is used as fungal insecticide in Bio-control programs?

    1. Trichoderma viridi

    2. Phytophthora parasitica

    3. Beauveria bassiana

    4. Aspergillus niger

  12. Which one of the following pairs is NOT correctly matched?

      • Blackarm
      • Phymatoirichum omnivoriuim
      • Root rot
      • Rhizoctonia solani
      • Angular leaf spot
      • Puccinia stakmanii
      • Wilt
      • Fusarium oxysporum sp. Vasinfectum
  13. Which one of the following structures does a fungus produce so that it survives for a very long period?

    1. Conidia

    2. Zoosperes

    3. Hyphae

    4. Sclerotia

  14. Mycorrhizal association controls root affecting pathogens in plants because

    1. Mychorrhizal fungi colonize the roots and acts as a barrier during infection

    2. Mychorrhizal fungi helps in phosphorus uptake

    3. Mychorrhizal fungi help during stress and shock

    4. Mychorrhizal fungi produce toxins against pathogens

  15. Match List I with List II and select the correct answer:

    List-I (Fungicides) List-II (Mechanism of action)
    1. Oxathin

    2. Griseofulvin

    3. Ziram

    4. Elemental sulphur

    1. Chelation

    2. Inactivation of enzyme

    3. Interference with cytoplasm membrane

    4. Lysis of fungal hyphae

    • A
    • B
    • C
    • D
      • 4
      • 3
      • 1
      • 2
      • 3
      • 4
      • 2
      • 1
      • 4
      • 3
      • 2
      • 1
      • 3
      • 4
      • 1
      • 2