Bacteria can convert atmospheric nitrogen into ammonia, Several form symbiotic associations with higher plants is given below;

               HOST PLANT                                                                          N-FIXING SYMBIONTS

A) Gunnera                                                                            i) Frankia

      B) Azolla                                                                                ii) Acetobacter

C) Leguminous                                                                     iii) Azospirillum

             D) Actinorhizal                                                                      iv) Nostoc

             E) Sugarcane                                                                         v) Anabaena

             F) Miscanthus                                                                       vi) Sinorhizobium

Which of the following combination with the host plants and n-fixing symbionts is CORRECT?

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#Question id: 37964

#Plant Biotechnology

Assertion (A): The suppression of 'late' pollen maturation genes is a critical step for successful androgenesis. 

Reason (R): The expression of these 'late' genes promotes the normal gametophytic pathway, preventing the switch to embryogenesis.

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#Question id: 37965

#Plant Biotechnology

Assertion (A): During the induction phase of pollen culture, total protein synthesis is completely halted. 

Reason (R): Existing proteins are suppressed, and new proteins like napin (in Brassica napus) are synthesized.

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#Question id: 37966

#Plant Biotechnology

Assertion (A): Commitment to androgenesis is achieved primarily by the abolition of pollen maturation gene expression. 

Reason (R): During induction, several hundred genes are upregulated or downregulated to facilitate the developmental switch

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#Question id: 37967

#Plant Biotechnology

Assertion (A): Responsive pollen in culture always develops directly into a globular embryo. 

Reason (R): The developmental fate (embryo vs. callus) depends on the plant species.

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#Question id: 37968

#Plant Biotechnology

Assertion (A): In cereals like rice and wheat, the choice between embryo or callus formation can be manipulated. 

Reason (R): Modifying the medium composition in these species can induce either embryos or calli.

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#Question id: 37969

#Plant Biotechnology

Statement I: Cold treatment (3–6°C) helps in retarding the aging of the anther wall, thereby allowing more microspores to switch from gametophytic to sporophytic development.

Statement II: Maize responds best to standard cold treatment temperatures of 3–6°C rather than higher temperatures like 14°C