Haploid structure in Funaria - Protonema

Protonema is the haploid structure in Funaria. It is a filamentous, green, and branched structure that arises from the germinated spore. The protonema is the first stage in the life cycle of the moss. It grows and develops into the leafy gametophyte plant of Funaria.

Features of Protonema

- Green filamentous structure: The protonema is a green, filamentous structure that is branched and grows in a zigzag pattern. The green color is due to the presence of chlorophyll, which helps in photosynthesis.

- Haploid structure: The protonema is haploid, which means it has a single set of chromosomes. It arises from the germinated spore, which is also haploid.

- Anchorage and absorption: The protonema helps in anchorage and absorption of water and nutrients from the soil. It also helps in the attachment of the gametophyte plant to the substrate.

- Development into gametophyte: The protonema develops into the gametophyte plant of Funaria. It gives rise to the leafy shoots, which bear the sex organs of the plant.

Importance of Protonema

- Reproduction: The protonema is important for the sexual reproduction of Funaria. It gives rise to the male and female sex organs, which produce the gametes. The fusion of gametes leads to the formation of the diploid sporophyte plant.

- Survival: The protonema helps in the survival of the moss plant. It anchors the plant to the substrate and absorbs water and nutrients, which are essential for growth and development.

- Adaptation: The protonema is an adaptation of the moss plant to its environment. It helps in the colonization of new habitats and the spread of the species.

Conclusion

In conclusion, the haploid structure in Funaria is the protonema. It is a green, filamentous, and branched structure that develops into the gametophyte plant. The protonema is important for the survival and reproduction of the moss plant.

Funaria exhibits gametophytic (n) as well as sporophytic (2n) generation in its life cycle. The gametophytic (haploid) generation is represented by a short-lived protonema which produces spermatozoids in antheridium of male shoot and egg in archegonium of the female shoot.
So the correct option is D