Question

Apospory is direct formation of _________________
A. Gametophyte from sporophyte
B. Gametophyte from gametophyte
C. Sporophyte from gametophyte
D. Sporophyte from sporophyte

Answer 1

In the life cycle of the plants and algae, the gametophyte is one of the alternating phases. It represents the sexual phase of the life cycle and develops sex organs which further produces gametes. The second phase is represented by the sporophyte.

Complete answer:
Apospory can be defined as the development of 2n gametophytes. The gametophytes arise without meiosis and spores from vegetative, or nonreproductive cells. These vegetative cells are known as the sporophyte. This process is marked by the absence or reductional division or the meiotic division. Pringsheim was the first scientist who demonstrated a case of apostrophe, sometimes called apomixis.
The development of the gametophyte from the sporophyte without the formation of spores that has arised from meiotic division is apostrophe. The spore from the mother cell does not undergo meiosis. In other words, it can be defined as the development of an embryo of a flowering plant outside the embryo sac. The development of the embryo takes place from a cell of the nucellus or chalaza. Apospory is the production of gametophyte directly from diploid cells of the sporophytes without any spore formation. This condition is seen in certain ferns and mosses.
Apomixis is also known as asexual seed formation in angiosperms. It occurs either sporophytic or gametophytically. The seeds arise through adventitious embryony. In other conditions, female gametophyte or the embryo sac produces an unreduced non-meiotically divided egg which further develops into an embryo.
The development of sporophytes without gametes and syngamy from vegetative cells of the gametophyte is known as apogamy. In apogamy, the sporophyte arises directly from the gametophyte.

Hence, the correct answer is option (A).

Additional information:
Development of gametophyte without any reductional division is more commonly exhibited by algae. The absence of normal meiotic condition is very common in higher plants of about more than 35 families of plants. In families such as Gramineae, Rosacea, Compositae and Rutaceae exhibit the absence of meiotic division.

Note: The development of the sexual phase or the reproductive phase from the unreduced division in algae and plants are known as apospory. In this process, the gametophyte or the cells that represent the sexual phase, arise from the sporophytes without any type of meiotic division. Thus, the direct gametophytic development from the sporophytes are known as apospory.