Question

How do fertilization and zygote formation take place in pteridophytes?

Answer 1

Fertilization in Pteridophytes:

1. Fertilization is the process of fusion of male and female gametes to produce a zygote.
2. Pteridophytes belong to the division of the plant group which comprises ferns and their relatives.
3. They are vascular plants (have xylem and phloem for transportation of food and water).
4. They have roots, stems, and shoots, but no flowers.
5. Pteridophytes go through internal fertilization as a fusion of male and female gametes occurs inside the archegonium.
6. Fertilization in pteridophytes occurs inside water.
7. The cap cells of antheridia (male reproductive organ) release antherozoids (male sex gamete) when a film of water flows between substratum and prothallus (gametophyte in fern) while pushing down the antheridia.
8. The haploid antherozoids (n DNA) are chemotactically attracted to the archegonium and swim towards it.
9. They are attracted to the malic acid secreted by the mucilaginous mass.
10. The antherozoids swim down the neck of archegonium.
11. One of the male antherozoids fuses with the egg to form a zygote.
12. Hence, fertilization results in the formation of a diploid zygote.