Question

Double Fertilisation occurs in
A) pinus
B) Selaginella
C) Funaria
D) Dalbergia/capsella

Answer 1

Hint:Fertilisation is a process where male and female gametes which are diploid in condition are produced from male and female part of an organism which later fuses to form a haploid zygote. Fertilisation process occurs in both plants and animals but Double Fertilisation is a specialised form of Fertilisation which occurs only in a particular class of plants.

Complete answer:
Double Fertilisation is a specialised form of Fertilisation process in which there is Fusion of megagametophyte or embryo sac which is a female gametophyte along with two male gametes called sperms. When a pole grain sticks to stigma, pollen grains starts to germinate a table like structure called as pollen tubules due to the moisture absorbed from the surrounding, pollen tube is responsible to carry two Male nuclei and penetrate into embryo sac thereby allowing the fusion of two male nuclei to one embryo sac, which contains 8 cells, where 3 are antipodal cells, 2 are polar central cells, 2 are synergids and a single egg cell.

One among the two sperms entered embryo sac fuses with egg cell and form a diploid zygote and the process is called as syngamy whereas the other sperm fuses with the polar bodies and forms triploid nucleus and the process is called as triple fusion which is also called as endosperm. For all the above steps to take place the presence of flowers is the most important aspect of a plant. Therefore Double Fertilisation occurs in angiosperms, Dalbergia and capsella are angiosperms.

Hence the correct answer is Option D.

Note:Plants mentioned in the rest of the options such as pinus, funaria and selaginella don’t belong to angiosperms and therefore they do not have flowers as their reproductive organ. Double fertilization increases the viability of the seeds of angiosperms. It utilizes both the male gametes produced by the pollen grains.