Plant Kingdom

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01

Asexual reproduction: By fragmentation of thalli

e.g. Marchantia, (NEET 2013) or by the formation

of gemmae (sing. gemma). Gemmae are green,

multicellular, asexual buds that develop in small

receptacles (gemma cups) on the thalli. Gemmae

detach from the parent body and germinate to

form new individuals.

02

Sexual reproduction: Male and female sex organs

are produced on the same or different thalli.

Sporophyte is differentiated into a foot, seta and

capsule. After meiosis, spores are produced within

the capsule. These spores germinate to form free-

living gametophytes.

MØSSËS

The predominant stage of the life cycle of a moss is the gametophyte. It

consists of two stages.

Protonema stage: The first stage which develops directly from a spore. It

is a creeping, green, branched and frequently filamentous stage.

Vegetative reproduction: By fragmentation and budding in the

secondary protonema.

Leafy stage: The second stage which develops from the secondary

protonema as a lateral bud. They consist of upright, slender axes bearing

spirally arranged leaves. They are attached to soil through multicellular

and branched rhizoids. This stage bears the sex organs.

Sexual reproduction: The antheridia & archegonia are produced at the

apex of leafy shoots. After fertilisation, zygote develops into a sporophyte,

consisting of a foot, seta and capsule. The sporophyte in mosses is more

elaborate than that in liverworts. The capsule contains spores. Spores

are formed after meiosis. Mosses have an elaborate mechanism of spore

dispersal. E.g. Funaria, Polytrichum and Sphagnum.