Question

The diploid cells of gametophyte in Selaginella gives rise to diploid sporophyte. Identify the name of the process involved.

• A. Apogamy
• B. Apospory
• C. Fragmentation
• D. Protonema

Answer 1

The correct option is A

Apogamy

The correct option is A.

Explanation of the correct option:

1. Apogamy is the process in which the diploid cells of the gametophyte in Selaginella give rise to the diploid sporophyte.
2. Lang found apogamy in a fern in which embryos under favorable conditions and are formed only sexually.
3. Apogamy is the development of a plant without the union of gametes.
4. It involves the development of a sporophyte from a gametophyte without fertilization.

Explanation of the incorrect option:

Option B:

1. Apospory is the development of 2n gametophytes without meiosis and spores from vegetative or non-reproductive cells of the sporophyte.
2. The phenomenon of apospory was first discovered by Druery.

Option C:

1. Fragmentation is a type of asexual reproduction in which an organism simply breaks into individual pieces at maturity.
2. Spirogyra undergoes fragmentation which results in many filaments.
3. The advantage for the organism as any body part can develop into a complete organism.
4. The disadvantage is that the offsprings produced are the exact copies of their parents, and the chances of variation are very low.

Option D:

1. The protonema, which grows directly from the germinating spore, is in most mosses an extensive, branched system of multicellular filaments that are rich in chlorophyll.
2. The protonema stage in liverworts is usually called sporeling in other bryophytes.

Final answer: Apogamy is the process in which the diploid cells of the gametophyte in Selaginella give rise to the diploid sporophyte.