Question

Which one of the following event can be considered highly evolved according to the theory of progressive sterilization of sporogenous tissue and sporophyte?

• A. Conversion of entire sporogenous tissue into the spores as in Riccia
• B. Conversion of part of sporogenous tissue into the sterile nurse cells as in Sphaerocarpos
• C. Sterilization of part of Sporophyte by the formation of foot, seta, columella, operculum and peristome as in Funaria
• D. Sterilization of Sporophytes by the formation of foot and elaters as in Marchantia

Hint:

More non-reproductive structures in the sporophyte = more evolved. Funaria has the most elaborate sporophyte among the options.

Answer 1

The Correct Option is C

Step 1: Concept
Progressive sterilization theory of sporophyte evolution in bryophytes.

Step 2: Meaning
Greater sterilization of the sporophyte (more parts becoming non-spore-producing) indicates higher evolutionary advancement.

Step 3: Analysis
(A) All sporogenous tissue $\rightarrow$ spores: no sterilization --- most primitive.
(B) Some sporogenous tissue $\rightarrow$ nurse cells: partial sterilization of sporogenous tissue.
(C) Sporophyte forms foot, seta, columella, operculum, and peristome (multiple non-spore-producing structures): highest degree of sterilization --- most evolved.
(D) Foot and elaters only: less sterilization than (C).

Step 4: Conclusion
Funaria (C) shows the highest evolutionary advancement through extensive sporophyte sterilization. Final Answer: (C)