Question

In Sphagnum, the sporogonium is elevated by a special gametophytic structure known as:

• A. Pseudopodium
• B. Perichaetium
• C. Antheridium
• D. Amphithecium

Hint:

Remember the key difference: In most mosses, the capsule is raised by the \textbf{seta} (part of the sporophyte, 2n). In {Sphagnum}, it's raised by the \textbf{pseudopodium} (part of the gametophyte, n). 'Pseudo' means false, so it's a 'false stalk' because it's not a true seta.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The question asks for the name of the structure that elevates the mature sporophyte (sporogonium) in the moss genus {Sphagnum}. This is a key feature that distinguishes {Sphagnum} from many other mosses.
Step 2: Detailed Explanation:
In the life cycle of a typical moss, the sporophyte develops from the zygote while attached to the gametophyte. The sporophyte consists of a foot, a stalk called the seta, and a capsule. The elongation of the seta (a sporophytic, diploid tissue) is what lifts the capsule up for better spore dispersal. However, in {Sphagnum} (peat moss), the seta remains very short and does not elongate significantly. Instead, after fertilization, a stalk-like structure develops from the gametophyte tissue of the archegonial branch, just below the foot of the sporophyte. This gametophytic (haploid) stalk elongates and pushes the entire mature sporogonium upwards. This structure is called a pseudopodium, which means "false foot". Let's look at the other options:

Perichaetium: The collective name for the modified leaves surrounding the archegonia (female sex organs).
Antheridium: The male sex organ in bryophytes.
Amphithecium: A layer of cells in the developing embryo of a moss that gives rise to the capsule wall.
Step 3: Final Answer:
The special gametophytic structure that elevates the sporogonium in {Sphagnum} is the pseudopodium.