Question

Spore dispersal by censor mechanism takes place in
A. Funaria
B. Selaginella
C. Fern
D. Pinus

Answer 1

Hint: Bryophytes do not bear any seeds and grow with the help of spores they produce. True roots, stems or leaves are absent in bryophytes. The male organ antheridium produces antherozoids which fuses with the egg produced from archegonium to produce the zygote. Zygote does not undergo meiotic division immediately and forms a multicellular short-lived sporophyte. The sporophyte is attached to the photosynthetic gametophyte and derives nutrition from it. The sporophyte bears the haploid spores formed due to meiosis in some cells of the sporophyte. When these spores germinate, gametophyte is formed.

Complete answer:
Censor mechanism of spore dispersal is the adaptive mechanism by certain plants that do not bear seeds. In this mechanism, spores are dispersed with the help of wind currents. The foot, seta and capsule are the three parts of the differentiated sporophyte. The spores are produced through meiosis in a capsule. The spores are dispersed by wind currents and when they land on a suitable surface for growth, they germinate.
The capsules of mosses (Funaria) are very strong and complex and consist of an operculum and peristome. Funaria opens its capsule under dry conditions to favour long-distance dispersal. As a result of water loss by the annulus, the operculum is shed. Due to which the peristome bends down and the spores shed out of the capsule and dispersed all over the place by wind currents, when landed on a suitable surface for growth they germinate.
Thus, the correct answer is option A:- Funaria.

Option ‘A’ is correct

Note:
The sporophytes of bryophytes are not free-living. The predominant stage of the life cycle of a moss is gametophyte where the first stage is protonema (directly develops from a spore) and the second stage is leafy stage which develops from the secondary protonema.