Question

Explain sexual reproduction in plants. [textbook question 11]

Answer 1

Answer:

• Plants reproduce sexually with the help of flowers.
• Androecium and gynoecium are male and female parts of the flowers respectively.
• In the carpel, the ovule undergoes meiosis and forms embryo sac.
• A haploid egg cell and two haploid polar nuclei are present in each embryo sac.
• The pollen grains from the anther reach the stigma of flower by the process of pollination. They germinate here on the stigma.
• As a result of germination, long pollen tube and two male gametes are formed.
• The pollen tube travels through the style of the flower and the male gametes present in the pollen tube are transferred to the embryo sac in the ovary. Upon reaching there, the tip of the pollen tube bursts releasing two male gametes in the embryo sac.
• One male gamete unites with the egg cell and forms a zygote. While another male gamete unites with two polar nuclei forming the endosperm.
• Because there are two nuclei participating in this process, therefore it is called double fertilization.
• After fertilization ovule develops into a seed and the ovary forms a fruit. When the seed again gets favourable conditions, it can produce a new plant.