Question

Anuradha observed a section of an ovary and compared it with a section of a fruit. She was not able to understand how the ovules became seeds. Can you explain it to her?​

Answer 1

How ovules become seeds?

★ Introduction: In plants, pollination is followed by fertilization.

★ Main answer:

• Once the pollen grains are deposited on the stigma, they form a long tube like structure called pollen tube
• Pollen tube reaches through the style and reaches ovary where ovules are present.
• Pollen tube releases 2 male gamates into the embryo sack.
• Embryo sack of the ovule contains egg cells. This egg cell fuses with male gamates to form zygote.
• The other male gamate fuses with 2 polar nuclei. This process is called Triple fusion. Zygote after several divisions, matures into embryo.

★ Conclusion:

Thus, inside each embryo sack, fertilization occurs 2 times and is called double fertilization.

After fertilization,

Ovary develops into fruit and

Ovules develop into seed