CBSE Class 12-science Answered

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Answer to one of your questions in given below: 

Role of pollination in fruit formation:

• It prevents the abscission or dropping of the ovary, which would otherwise take place along with the withering of other floral parts.
• Pollen grains contain small amount of auxin, which together with limited amount of additional auxin from the carpellary tissues support the initial growth of the ovary.
• Pollen tube formed from a pollen grain stimulates auxin synthesis inside the pistil. As the pollen tube grows, synthesis of auxin inside the gynoecium progresses.
• As soon as the pollen tube performs fertilisation, it induces the fertilized ovules to produce various types of growth hormones not only for themselves but also for the entire ovary.

Role of seed development in fruit formation:

• The developing seeds produce all the three types of growth promoting hormones in plants- auxins, gibberellins and cytokinins.
• They not only help in the growth of the seeds, but also the growth of the entire fruit.
• There have been instances in apples where deformity or depression occurs in the region where internal seed formation is either poor or absent.

Thus, we can say that pollination and seed formation are very crucial for fruit formation.

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