In some of the liverworts, spore dispersal is aided by

The correct option is elaters.

Step-by-Step Explanation:

1. Understanding Liverworts: Liverworts are primitive, non-vascular land plants belonging to the division Bryophyta (specifically, the class Hepaticopsida). Their sporophyte generation is dependent on the gametophyte and consists of a foot, seta, and capsule.

2. What are Elaters? Inside the capsule of many liverworts (such as Marchantia), some of the sporogenous cells do not form spores but instead differentiate into specialized, elongated, spindle-shaped cells called elaters. These cells have helical or spiral thickenings of hygroscopic material on their inner walls.

3. Mechanism of Spore Dispersal: Elaters are highly hygroscopic, meaning they readily absorb and lose moisture from the surrounding environment. When the capsule matures and splits open, the elaters lose moisture, causing them to twist, coil, or uncoil rapidly. This sudden movement creates a jerking motion that helps untangle the spores and ejects them into the air currents, thereby aiding in effective spore dispersal.

4. Why other options are incorrect:
• Indusium: This is a protective, membranous covering that shields the sporangia (sori) in ferns, not liverworts.
• Peristome teeth: These are tooth-like structures found at the rim of the capsule in true mosses (like Funaria) that regulate spore release, not liverworts.
• Calyptra: This is a protective hood or cap covering the young sporophyte capsule, derived from the archegonial wall, and does not actively aid in spore dispersal using hygroscopic mechanisms like elaters.