Module: | Pollination & Outbreeding Devices
Q63: Consider the following statements regarding the Nemec phenomenon:
1. The Nemec phenomenon refers to the highly unusual and abnormal development of a pollen grain into a multicellular, embryo sac-like structure.
2. This botanical anomaly was first historically documented in the anthers of Hyacinthus orientalis by the scientist Nemec.
3. This phenomenon proves that the male gametophyte has completely lost its cellular totipotency and is biologically incapable of mimicking female developmental pathways.
Which of the above statements is/are correct?
2. This botanical anomaly was first historically documented in the anthers of Hyacinthus orientalis by the scientist Nemec.
3. This phenomenon proves that the male gametophyte has completely lost its cellular totipotency and is biologically incapable of mimicking female developmental pathways.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, whereas Statement 3 is the exact opposite of the scientific conclusion.
In standard angiosperm reproduction, the microspore (pollen grain) follows a strict developmental pathway to become a 2-celled or 3-celled male gametophyte.
However, in 1898, the botanist B. Nemec observed a bizarre occurrence in the petaloid anthers of the hyacinth plant (Hyacinthus orientalis). He discovered that some pollen grains underwent multiple free-nuclear divisions followed by cellularization, organizing themselves into an 8-nucleate structure that structurally mimicked the female embryo sac.
Statement 3 is fundamentally incorrect because the Nemec phenomenon causally proves the exact reverse: it demonstrates that the microspore retains remarkable totipotency.
Under specific stress or genetic triggers, the haploid male spore possesses the latent genetic programming to entirely shift its developmental fate and construct female-like reproductive architecture.
In standard angiosperm reproduction, the microspore (pollen grain) follows a strict developmental pathway to become a 2-celled or 3-celled male gametophyte.
However, in 1898, the botanist B. Nemec observed a bizarre occurrence in the petaloid anthers of the hyacinth plant (Hyacinthus orientalis). He discovered that some pollen grains underwent multiple free-nuclear divisions followed by cellularization, organizing themselves into an 8-nucleate structure that structurally mimicked the female embryo sac.
Statement 3 is fundamentally incorrect because the Nemec phenomenon causally proves the exact reverse: it demonstrates that the microspore retains remarkable totipotency.
Under specific stress or genetic triggers, the haploid male spore possesses the latent genetic programming to entirely shift its developmental fate and construct female-like reproductive architecture.