Question

Double fertilization and triple fusion were discovered by.
A. Hofmeister
B. Nawaschin and Guignard
C. Leeuwenhoek
D. Starburger

Answer 1

Hint: The angiosperm are the most advanced plants on the Earth as they are flower bearing as well as fruit bearing plants. They produce endosperm for the nourishment of seed by undergoing a double fertilization process.

Complete Answer:
- Double fertilization is the phenomenon in which two male gametes fuse with the female gametes and also with the secondary nucleus to produce the zygote and the endosperm.
- During this phenomenon, two male gametes are involved in the fertilization process one gamete is fused with female gamete and zygote is formed that developed into seed, another gamete fused with the secondary nucleus of the central cell to form the triploid primary endosperm nucleus that forms the endosperm. This endosperm gives nourishment to the developing embryo.
- The triple fusion is the phenomenon observed in many angiosperm in which the fusion involve two polar nucleus that formed in double fertilization process in the seed, this give rise to triploid nucleus that is termed as primary endosperm nucleus, as mentioned above also, that later form the endosperm.
- Now, the double fertilization and the triple fusion is first discovered by Nawaschin and Guignard. In their experiment they had used Lilium and Fritillaria, they observed that in both the angiosperm the two male gamete fuses with two polar nuclei and produced the triploid endosperm nucleus that is because of the triple fusion process and these two gametes act together are termed as double fertilization.

Hence, the correct option is ‘B’. Nawaschin and Guignard.

Note: In gymnosperm, they do not undergo triple fusion as they are non-flowering plants they produce diploid zygote by the fusion of pollen grains and ovule. The pollen grain is the male gametophyte and the ovule is the female gametophyte. The seed gets nourishment directly from the plants.