Question

What is the significance of fertilization? Enumerate the methods of fertilization as seen in a flowering plant.

Answer 1

1. The fertilization of an egg initiates the life.
2. It results in mixing of genes from two different individuals, thus producing a totally unique set of chromosomes for a new individual
3 Fertilization ensures diploidy of the organism by fusion of haploid male and female gametes.
4 Fertilization provides new genetic constitution to the zygote.
5 Fertilization process increases the metabolic activities and the rate of protein synthesis of the egg.
6 Fertilization initiates the process of embryogenesis

Process of fertilization in plants

1 The pollination occurs when there is transfer of anther on the stigma.
2 The pollen grain germinates as soon the carpel gets pollinated.
3 The pollen Tube starts to grow after the germination of the pollen grain
4 The pollen tube travels towards the ovary.
5 The pollen grain attaches itself to the stigma and the pollen tube enters the ovule.
6 The pollen tube then breaks into the ovule bursts into the embryo sac. In the embryo sac one of the male nucleus fuses with the egg nucleus and forms a diploid zygote. This is called syngamy
7 The other male nucleus enters into the embryo sac and fuses with the secondary nucleus. This gives rise to the primary endosperm nucleus or also called as a triploid nucleus. The formation of PEN is called as Triple fusion
8 After the process of fertilization the ovary swells up and develops into a fruit.