Question

In angiosperms, sometimes it is seen that an embryo maybe formed from the deploid cells of the nucellus. It is a case of _________________

• A. Apospory
• B. Parthenocarpy
• C. Parthenogenesis
• D. Polyembryoniy

Answer 1

Answer:

A. Apospory

• In angiosperms, apospory is a form of gametophytic apomixis where a diploid (2n) embryo sac develops directly from a somatic cell of the ovule—most commonly a cell of the nucellus or integument—without meiosis.

• Because the embryo sac is formed from a diploid sporophytic cell, it is genetically identical to the mother plant.

• The unreduced (2n) egg cell inside this aposporous embryo sac can then develop into an embryo parthenogenetically (without fertilization).

• Thus, the sequence is:
  Nucellar (diploid) cell → diploid embryo sac (apospory) → diploid embryo (parthenogenesis).