NEETBotanySexual Reproduction in Flowering Plants
A typical angiosperm embryo sac is 8-nucleate and 7-celled at maturity. Which of the following statements correctly describes the developmental process from the functional megaspore that leads to this specific configuration?
Options
- AThe functional megaspore undergoes three successive free nuclear mitotic divisions, followed by cell wall form
- BThe functional megaspore undergoes three successive mitotic divisions, where cytokinesis immediately follows e
- CThe functional megaspore undergoes three successive meiotic divisions to directly produce eight haploid nuclei
- DThe functional megaspore undergoes two free nuclear mitotic divisions followed by a final mitotic division wit
Correct answer
A. The functional megaspore undergoes three successive free nuclear mitotic divisions, followed by cell wall form
Step-by-step solution
The development of a typical angiosperm embryo sac (Polygonum type) from a functional megaspore involves three successive mitotic divisions. These divisions are strictly free nuclear, meaning that karyokinesis is not immediately followed by cytokinesis, resulting in an 8-nucleate syncytium. Only after the 8-nucleate stage are cell walls laid down. Six of the eight nuclei become surrounded by cell walls and organise into distinct cells (three in the egg apparatus and three antipodals), while the remaining two polar