Simulation · Biology · Class 11
Walk a moss through its life
From the lesson Liverworts and mosses in Plant Kingdom. Change the values and watch what happens.
Walk a moss through its lifeBiology · Class 11
The idea behind it
NCERT §3.2.1–3.2.2
- Liverworts grow in moist, shady spots: stream banks, marshy ground, damp soil, tree bark and deep in woods.
- A thalloid liverwort such as Marchantia has a dorsiventral thallus pressed flat against the ground. Leafy liverworts carry tiny leaf-like appendages in two rows on stem-like parts.
- Liverworts reproduce asexually by fragmentation of the thallus, or by gemmae (singular gemma): green, multicellular asexual buds formed in small cups, the gemma cups, on the thallus. Gemmae break off and grow into new plants.
- Male and female sex organs may be on one thallus or on separate thalli. The sporophyte has a foot, a seta and a capsule; spores form in the capsule after meiosis and grow into free-living gametophytes.
- In mosses the gametophyte is the main stage, and it has two parts. The protonema grows straight from a spore and is creeping, green, branched and often filamentous.
- The leafy stage grows as a lateral bud from the secondary protonema. It has upright, slender axes with spirally arranged leaves, held in the soil by multicellular, branched rhizoids, and it carries the sex organs.
- Mosses reproduce vegetatively by fragmentation and by budding in the secondary protonema. Antheridia and archegonia form at the tips of the leafy shoots.
- After fertilisation the zygote forms a sporophyte of foot, seta and capsule, more elaborate than a liverwort's. Spores form in the capsule after meiosis, and mosses have an elaborate way of dispersing them. Examples: Funaria, Polytrichum, Sphagnum.