Question

Double fertilization is?

• A. fusion of one male gamete with two polar nuclei.
• B. fusion of two male gametes with one egg.
• C. syngamy and triple fusion.
• D. fusion of two male gametes of a pollen tube with two different eggs

Answer 1

The correct option is C

syngamy and triple fusion.

The correct option is C.

Explanation for the correct option:

1. The process of double fertilisation is exclusive to angiosperms.
2. One male gamete that is close to the egg unites with the egg nucleus in the embryo sac following the release of two male gametes by the pollen tube.
3. This process, known as syngamy, produces a zygote.
4. In a process known as triple fusion, the other male gamete fuses with the secondary nucleus to create a triploid primary endosperm mother cell.
5. Double fertilisation refers to the simultaneous occurrence of syngamy and triple fusion in the embryo sac.

Explanation for the incorrect answers:

Option A:

1. A zygote is formed when one of the male gametes unites with an egg cell.
2. An embryo develops from a zygote.
3. The two polar nuclei of the second male gamete fuse, resulting in the development of endosperm.
4. Finally, the above results in the production of three nuclei, which is known as triple Fusion.

Option B:

The fusion of two male gametes with one egg, is the step of double fertilization, it cannot describe the whole process.

Option C:

Fusion of two male gametes of a pollen tube with two different eggs, cannot describe the double fertilization.

Final answer: Double fertilization includes both syngamy and triple fusion.