Question

In............... type, the embryosac is formed by the micropylar dyad cell.

• A. Allium
• B. Endymion
• C. Oenothera
• D. Polygonum

Answer 1

Answer:

B. Endymion

• The formation of the embryo sac from a single megaspore is termed as monosporic development.

• In Endymion (also known as Scilla), a genus of flowering plants in the family Asparagaceae, the embryo sac development follows a specific pattern.

• Typically, in monosporic development, one of the four megaspores formed after meiosis degenerates, and the functional megaspore develops into the embryo sac.

• In the Endymion type of embryo sac development, it is specifically the micropylar dyad cell that undergoes further development to form the embryo sac.

• This is a deviation from other common types of monosporic development like the *Polygonum* type, where the chalazal megaspore is usually functional.

• The development in Endymion involves the functional megaspore undergoing three successive mitotic divisions to form an eight-nucleate embryo sac.