Moss Life Cycle Labeling Quiz

All 14 stages and parts on the diagram

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Spore to plant 5

Spores Tiny grains that drift on the air. Each can start a new moss.
Protonema The green branching thread a spore grows into.
Bud It forms on the protonema and grows into a leafy plant.
Gametophyte (leafy plant) The leafy green moss plant. It makes the sperm and the eggs.
Rhizoids Fine threads that anchor the plant. They are not true roots.

Sperm and egg 4

Antheridium The male organ. It makes the sperm.
Sperm Tiny swimmers from the antheridium. They need water to reach the egg.
Archegonium The female organ: a flask with a long neck and one egg.
Egg It sits in the base of the archegonium. A sperm fertilizes it.

The sporophyte 5

Young sporophyte It grows from the fertilized egg, on top of the leafy plant.
Seta (stalk) The long stalk of the sporophyte. It lifts the capsule into the air.
Calyptra (cap) A loose cap over the capsule, left over from the archegonium.
Capsule (sporangium) The urn at the top of the seta. The spores form inside it.
Operculum (lid) The lid of the capsule. When it comes off, the spores can leave.

How this list was compiled: Every name was checked on 2026-09-30 against sources read that day; a name is kept only when two of them use it. (1) John N. Martin, Botany for Agricultural Students, 1919, public domain, https://archive.org/details/botanyforagricul00mart (true mosses: the leafy green plant is the gametophyte, with rhizoids; club-shaped antheridia and flask-shaped archegonia with long necks stand on the stem tip, in many mosses on the same plant, in others on separate plants; the sperms swim down the neck when there is moisture and fertilize the egg; the fertilized egg grows in place into the sporophyte, with a foot, a stalk called the seta and a sporangium, or capsule, in which the spores are produced; the enlarged archegonium is carried up as a pointed cap; the lid, or operculum; a spore first produces a branching filament, the protonema, and the leafy plants grow from buds on it; one protonema may produce many buds). (2) Wikipedia, text only: Moss, https://en.wikipedia.org/wiki/Moss (the life cycle starts with a spore that germinates to produce a protonema; from it grows the gametophore, with stems and leaves; rhizoids anchor the plant; antheridia and archegonia; in the presence of water sperm swim to the archegonia; the sporophyte is a long stalk, the seta, and a capsule capped by the operculum, sheathed by the calyptra, the remains of the archegonium, which usually drops off once the capsule is mature; a mat of protonemata may grow several shoots, a clump of moss), Protonema, https://en.wikipedia.org/wiki/Protonema (the bud), Sporophyte, https://en.wikipedia.org/wiki/Sporophyte (the sporophyte develops from the zygote, the fertilized egg cell, within the archegonium; young sporophytes of a moss), and Archegonium, https://en.wikipedia.org/wiki/Archegonium . (3) C. Stuart Gager, Fundamentals of Botany, 1916, public domain, https://archive.org/details/fundamentalsofbo00gagerich (chapter XV, Life history of a moss: antheridia with sperms that bear two cilia; archegonia with a neck and a venter containing the egg; the capsule with its spores; the top of the archegonium carried up as a cap, the calyptra; the operculum). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain curves; own work, nothing traced. Licence: own work

How it works

This moss life cycle labeling quiz names a stage or a part and you tap it on the drawing: spore to leafy plant and the organs that make sperm and egg, much enlarged, then the stalk and capsule.

Read the full guide

Tell the look-alikes apart

The antheridium is the club-shaped sac and the archegonium the flask with a long neck. The protonema is the thread lying on the ground with a bud on it; the rhizoids are the threads under a leafy shoot. The young sporophyte is the thin spike on the first plant, and the seta is the long stalk on the next.

Haploid and diploid on the drawing

Everything in the first two steps is haploid: spores, protonema, bud, leafy gametophyte, sperm and egg. Fertilization starts the one diploid generation, the sporophyte, with its seta and capsule. The calyptra over the capsule is haploid all the same, because it is what is left of the archegonium.

Questions and answers

Where does meiosis occur in the moss life cycle?

Inside the capsule, the sporangium at the top of the seta. Spore-producing cells there divide by meiosis and form haploid spores, and each spore can start a new protonema.

Which generation is dominant in mosses?

The gametophyte, the haploid leafy plant. The sporophyte is short-lived and depends on it for water and most of its nutrients. In ferns and seed plants it is the other way around: the sporophyte is the dominant generation.

Is the protonema part of the gametophyte?

Yes. It is the earliest stage of the gametophyte. A spore grows into this branching thread, and the leafy shoots that rise from its buds belong to the same haploid generation.

Where is the zygote in the moss life cycle diagram?

In the base of the archegonium, where the egg sat. A fertilized egg looks the same as an egg in a drawing, so the quiz asks the egg and not the zygote. The young sporophyte grows from that spot.