Q.Observe the diagram given below :

Gemma cups are found on the thallus (upper surface) of liverworts such as Marchantia, and they house the vegetative reproductive bodies called gemmae.

Certain liverworts — the classic textbook example being Marchantia — reproduce vegetatively by producing small, green, multicellular, asexual bodies called gemmae. These gemmae develop inside small, cup-shaped structures called gemma cups, which are borne on the dorsal (upper) surface of the flat, ribbon-like gametophytic thallus. A gemma detaches from the cup ( …

Moss matches with Sphagnum, a common genus of moss.

Bryophytes are divided into liverworts, mosses (Class Bryopsida/Musci), and hornworts. Mosses have a dominant leafy gametophyte stage, with the sporophyte remaining attached to and dependent on it. Sphagnum, also called peat moss, is a well-known genus of moss that grows …

A moss spore germinates into a filamentous protonema before the leafy gametophore develops from it.

In bryophytes such as mosses, the dominant, photosynthetic phase is the gametophyte. Its development is two-staged:

1. A haploid spore germinates and grows into a green, branched, thread-like (filamentous) structure called the protonema, which creeps over the substratum like an alga.
2. From buds that arise on the protonema, upright, leafy gametophores (the familiar "moss plant" with a stem-like axis bearing spirally arranged leaves) develop; these bear the sex organs — antheridia (male) and archegonia (female). …

The protonema is the haploid, filamentous, juvenile stage of a moss that develops directly from a germinating spore.

In Bryophyta (specifically mosses, class Bryopsida), a haploid spore germinates to produce a green, branched, filamentous or thalloid structure called the protonema. Since it arises directly from a haploid spore by mitosis, the protonema itself is haploid. It bears l …

Liverworts and mosses together make up the plant division Bryophyta.

Bryophytes are commonly called the 'amphibians of the plant kingdom' because they need water for sexual reproduction (motile sperm must swim to the egg) even though the main plant body can live on land. Bryophyta is broadly divided into liverworts (class Hepaticopsida, e.g., Marchantia) and mosses (class Bryopsida, e.g., Funaria, Polytrichum). They lack true vascular tissue and true roots (rh …

True mosses (Bryopsida) have a comparatively long-necked archegonium containing about 6 to 10 neck canal cells, more than the shorter-necked archegonium of liverworts.

The archegonium (female sex organ) of a bryophyte is flask-shaped, with a swollen basal venter (containing the egg cell and a venter canal cell) and a narrow neck above it. Running down the neck is a vertical row of neck canal cells, which disintegrate at maturity to form a mucilaginous passage that the male gametes (antherozoids) swim through to reach the egg.

The exact number of neck canal cells is a taxonomically useful feature that differs between bryophyte groups: …

Liverworts are simple, thalloid bryophytes; Marchantia and Riccia are two common examples.

Liverworts belong to the class Hepaticopsida of the division Bryophyta. They usually grow in moist, shady habitats and have a flat, prostrate, dorsiventral thallus that is closely attached to the substrate by unicellular rhizoids. Vegetative reproduction commonly occurs by fragmentation or by gemmae (small multicellular bodies) formed in stru …

The gemma cup is Marchantia's vegetative-reproduction structure: a tiny cup on the thallus that produces and disperses asexual buds called gemmae.

Bryophytes like Marchantia (a liverwort) reproduce both sexually and vegetatively. The vegetative method uses small, saucer- or cup-shaped structures called gemma cups, which develop on the dorsal (upper) surface of the flattened, ribbon-like thallus.

• Inside each gemma cup, the thallus tissue produces small, green, lens-shaped, multicellular structures called gemmae, attached to the cup floor by a short stalk.
• Each gemma is genetically identical to the parent plant (an asexual/clonal propagule).
• Raindrops falling into the open cup splash the gemmae out; on reaching moist soil, each gemma germinates directly into a new thallus, without any fusion of gametes. …