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: 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.

Select the correct option from:

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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.

Select the correct option from:

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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

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#Question id: 37970

#Plant Biotechnology

Statement I: Hot treatment (e.g., 30°C for 24h) in Brassica stimulates embryogenesis by causing the dissolution of microtubules and displacement of the spindle.

Statement II: This thermal shock leads to normal division of the microspore nucleus.

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#Question id: 37971

#Plant Biotechnology

Statement I: Ethrel (2-chloroethylphosphonic acid) treatment increases haploid production by inducing multinucleated pollen grains.

Statement II: Pollen grains induced by Ethrel treatment are characterized by having a high density of starch grains.

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#Question id: 37972

#Plant Biotechnology

Statement I: Commitment to androgenesis is achieved mainly by the overexpression of pollen maturation ('late') genes.

Statement II: In wheat, the synthesis of a metallothionein-like protein during induction is regulated by Abscisic Acid (ABA).