How does the Protonema fit into the moss life cycle

A haploid moss spore germinates and gives rise to a protonema, a green multicellular tissue that superficially resembles a filamentous green alga. Under appropriate conditions, other moss cells can also be induced to form protonema. Buds form on the protonema producing the familiar “leafy” moss plant. …


What stage in the life cycle of a moss does the protonema represent?

A protonema (plural: protonemata) is a thread-like chain of cells that forms the earliest stage of development of the gametophyte (the haploid phase) in the life cycle of mosses.

What are the stages of life cycle of moss?

Similar to plants, the moss lifecycle is completed in two distinct stages – the gametophyte and the sporophyte. The term that describes this type of life history is called alternation of heteromorphic generations. In vascular plants the dominant stage of this lifecycle is the diploid generation.

What is the function of protonema in moss?

The protonema, which grows directly from the germinating spore, is in most mosses an extensive, branched system of multicellular filaments that are rich in chlorophyll. This stage initiates the accumulation of hormones that influence the further growth of newly formed cells.

What is the first life cycle of a moss?

The life cycle of most mosses begins with the release of spores from a capsule, which opens when a small, lidlike structure, called the operculum, degenerates. A single spore germinates to form a branched, filamentous protonema, from which a leafy gametophyte develops.

How does a moss reproduce?

Mosses reproduce by spores, which are analogous to the flowering plant’s seed; however, moss spores are single celled and more primitive than the seed. Spores are housed in the brown capsule that sits on the seta. … Some mosses have cups on their tops that produce sperm, these are male plants.

What feature of the moss life cycle differs from the life cycle of other land plants?

All bryophytes have a dominant gametophyte stage in their life cycle. During this stage, the plant is haploid and the sex organs that produce the gametes are developed. Bryophytes are unique compared to many other plant species in that they remain in this stage for long periods.

When moss spores germinate they form?

When a moss spore germinates it first develops a protonema. This is a filamentous to sheet-like growth form, often with a strong resemblance to an algal colony or a fern prothallus. In due course one or more stems grow from the protonema and leaves develop on the stems, giving rise to one or more leafy-stemmed plants.

Which phase in the life cycle of a moss consists of a leafy plant?

In mosses, as in liverworts and hornworts, the leafy shoots belong to the gametophytic phase and produce sex organs when they mature. The leafy shoots (often called gametophores, because they bear the sex organs) arise from a preliminary phase called the protonema, the direct product of spore germination.

Is moss multicellular or unicellular?

Although they share many superficial characteristics with algae, mosses are classified in the plant kingdom because they are multicellular organisms

Article first time published on

What do the moss life cycle and the fern cycle have in common?

Both mosses and ferns have gametophyte and sporophyte stages in their life cycle.

How are fern and moss life cycles similar?

Both mosses and ferns undergo alterations of generations. Both mosses and ferns are spore producing plants. Both mosses and ferns require water for the fertilization since their sperm cells consist of flagella. Both mosses and ferns prevent soil erosion.

How is the life cycle of a fern similar to the life cycle of a moss?

Also, both mosses and ferns show alternation of generation. But, the dominant phase of the life cycle of mosses is the haploid gametophyte generation, while the dominant phase of the life cycle of ferns is the diploid sporophyte generation. Therefore, this is another important difference between mosses and ferns.

What occurs in the life cycle of a moss but not in the life cycle of a gymnosperm?

In moss, sperm and egg cells are produced after haploid spores are separated from the sporophyte plant– occurs in the life cycle of a moss but not in the life cycle of a gymnosperm.

How does moss live?

Moss can survive in different habitats but it usually prefers shady areas of woodlands and forests that provide enough water. Moss can grow both on the trees and on the ground, but it can be also found on the rocks, under the water, on the clay…

What generation produces spores in the moss life cycle?

Life cycle of a moss (genus Polytrichum). The sporophyte generation is dependent on the photosynthetic gametophyte for nutrition. Cells within the sporangium of the sporophyte undergo meiosis to produce male and female spores, respectively.

How do the moss gametophyte and sporophyte stages obtain their energy?

Moss reproduces by the creation of spores held within sporophytes. These sporophytes have no photosynthetic capabilities, so they are dependent on the gametophytes for nutrition needs.

Which of the following structures in a moss life cycle are haploid and which are diploid?

Sporophytes are diploid, whereas gametophytes are haploid. Which of the following is true of the life cycle of mosses? The sporophyte generation is dominant. Spores are primarily distributed by water currents.

What land adaptations have moss spores developed?

The most important adaptation to land life which mosses have in common with other land plants is the presence of a thin cuticula that protects them against loss of water. Single-cell and multicellular rhizoids resembling root hairs can be found.

What is unusual about the reproductive cycle of a moss?

The mosses (and all bryophytes) have an alternation of generations life cycle that is unusual for two reasons: The haploid form is the dominant generation (larger, long-lived, and photosynthetic) The diploid form is the lesser generation (smaller, short lived and nutritionally dependent on the haploid form).

Where does fertilization take place in the moss life cycle?

In the moss life cycle, fertilization takes place in the archegonium of the gametophyte. Mosses have diploid and haploid generations. Gametophytes, spores, sperm, and eggs are all haploid.

What is the adaptation of moss?

Mosses are considered to be only partially adapted to land because they are non-vascular plants. Moss has adapted to life on land by having a thick cell wall that provides support. It also provides a special storage area for water and nutrients.

How are moss spores dispersed to new locations?

Mosses disperse their spores from a capsule that often is elevated above the shoot by a seta (capsule and seta together make up the sporophyte) anchored to the top of the moss shoot in cushion growing species or along the shoot in mat-growing species.

Which statement best describes fertilization in the moss life cycle?

Which statement best describes fertilization in the moss life cycle? Flagellated sperm swim in a film of water on the surface of the plant to reach an egg. The slender, rootlike structures found in nonvascular plants are called ____.

How do moss spores travel?

Moss can spread in different ways; spore dispersal through wind and insects, fragmentation and shoot growth. Fragmentation: Just a tiny part of moss can develop into a larger plant and spread over time to cover a large area. … It is very simple for moss to quickly spread along cracks between paving stones for example.

What does a spore of moss germinate into class 11?

by Biology experts to help you in doubts & scoring excellent marks in Class 11 exams. A spore of moss, on germination form protonema.

Are spores sperm?

The spore capsules are produced after the sperm have fertilized the eggs. Hence the spores are part of the sexual reproductive cycle. … A spore capsule is part of the sporophyte, which develops from a fertilized egg.

How are mosses and Pteridophytes different?

QuestionPteridophytes differ from mosses/ bryophytes in possessingType of AnswerText

How does Moss photosynthesis?

They are small (a few centimeters tall) herbaceous (non-woody) plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide and sunlight to create food by photosynthesis. … Mosses do not absorb water or nutrients from their substrate through their rhizoids.

What is the life cycle of a fern?

The life cycle of the fern has two different stages; sporophyte, which releases spores, and gametophyte, which releases gametes. Gametophyte plants are haploid, sporophyte plants diploid. This type of life cycle is called alternation of generations.

Which life cycle components only appear in mosses ferns?

Life cycle of ferns or mosses have two life stages; sporophyte generation and gametophyte generation.