Question

Describe about double fertilisation in pants...………… Class 10.

Answer 1

Answer:

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Double fertilization is a complex fertilization mechanism of flowering plants (angiosperms). This process involves the joining of a female gametophyte (megagametophyte, also called the embryo sac) with two male gametes (sperm). It begins when a pollen grain adheres to the stigma of the carpel, the female reproductive structure of a flower. The pollen grain then takes in moisture and begins to germinate, forming a pollen tube that extends down toward the ovary through the style. The tip of the pollen tube then enters the ovary and penetrates through the micropyle opening in the ovule. The pollen tube proceeds to release the two sperm in the megagametophyte.

The cells of an unfertilized ovule are 8 in number and arranged in the form of 3+2+3 (from top to bottom) i.e. 3 antipodal cells, 2 polar central cells, 2 synergids & 1 egg cell. One sperm fertilizes the egg cell and the other sperm combines with the two polar nuclei of the large central cell of the megagametophyte.

Answer 2

Explanation:

Double Fertilization :-

The process of double fertilization take place in angeospermic plants when pollen grain fall in stigma the male nucleus divide into male neuclous and tube neuclous. During second division the male gamates again divide to form to male neuclous one male neuclous fuses with egg and this process is called syngamy the second male neuclous fuses with secondary nucleus and the process is called triple fusion.