Sexual Reproduction in Flowering Plants Question 5
5. What is the fate of the male gametes discharged in the synergid?
(a) One fuses with the egg, other(s) degenerate(s) in the synergid.
(b) All fuse with the egg.
(c) One fuses with the egg, other(s) fuse(s) with synergid nucleus.
(d) One fuses with the egg and other fuses with central cell nuclei.
Show Answer
Answer : d
Hints & Solutions
(d) In flowering plants, out of the two male gametes discharged in synergids, one fuses with the egg and other fuses with the secondary or definitive nucleus present in central cell. $Egg(n)+1^{\text{st }}$ male gamete $(n) \to$ Zygote $(2 n)$ Secondary nucleus $(2 n)+2^{n d}$ male gamete $(n)$ $arrow$ Endosperm Nucleus(3n) (central cell nuclei) The synergid cells produce an attractant that guides the pollen tube to the female gametophyte and likely contain factors that control arrest of pollen tube growth, pollen tube discharge, and gamete fusion.
