Question

Explain nemec phenomena

Answer 1

Pollen embryo sacs are also called NEMEC PHENOMENON, as Nemec discovered them for the first time. According to Nemec, pollen embryo sacs are produced by the repeated divisions of vegetative nucleus while the generative nucleus degenerates.

Answer 2

Botanist, Bohumil Nemec had made researches with the anthers of the flowering plant species named Hyacinthus orientalis.

Under normal conditions, dominance of male potency was observed in the petaloid. Here, a male gametophyte was usually two or three nucleated.

But under abnormal conditions ( due to nechrohormones), dominance of female potency was observed. Here, a male gametophyte was 8 nucleated and he had named it as pollen embyrosacs. This female dominancy resulted in embryosac like male gametphytes.

Above phenomenon is called as Nemec-phenomenon.