Moss Life Cycle Diagram

Study Notes

Mosses are non-vascular plants belonging to Phylum Bryophyta, living in moist environments.
They have two life stages: haploid and diploid, both multicellular.
Haploid has male and female plants, reproducing sexually, while diploid has only one sporangium, reproducing asexually.
This change between haploid and diploid is known as the alternation of generations.
Mature moss plants, or gametophytes, can be either male or female.

Mature females have archegonia, holding female gametes, reproductive organs, and the egg.
Mature males have antheridia, holding male gametes, reproductive organs, and sperm.
Gametophytes are part of the haploid life stage and occur at the top of the plant.

Sporophyte structure is responsible for asexual reproduction and the diploid part of the cycle.
Sporophyte develops from a zygote, which undergoes mitosis, forming a sporangium.
Inside the sporangium, meiosis takes place, producing four genetically diverse cells (spores).

The cycle starts with two separate gametophytes, male and female, sexually reproducing.
Sperm meets an egg, resulting in a zygote, marking the beginning of the diploid phase.
The zygote undergoes mitosis, forming a sporangium, which produces spores.
Spores grow into new gametophytes, restarting the cycle.

n: represents one set of chromosomes, often used to describe the haploid stage.
2n: represents two sets of chromosomes, often used to describe the diploid stage.
Alternation of generations: the change between haploid and diploid stages in moss life cycle.
Fusion: the process of sperm meeting an egg, resulting in a zygote.
Meiosis: the process of producing genetically diverse cells (spores) in the sporophyte stage.

Moss reproduction involves two types: sexual and asexual.
Sexual reproduction occurs in the gametophyte stage, involving male and female gametes.
Asexual reproduction occurs in the sporophyte stage, involving only one plant.

Gametophyte: haploid, dominant, sexual reproduction, sperm and egg fusion.
Sporophyte: diploid, recessive, asexual reproduction, meiosis and spore production.

Antheridial head: holds the antheridium and eventually creates the sporangium.
Antheridium: produces sperm.
Archegonial head: produces eggs.
Bud: small, germinated spores.
Capsule: holds the spores.
Calyptra: protection over a forming capsule.
Early Embryo: pre-zygote cells, can be called germination or fusion.
Egg/Archegonium: where fertilization takes place, the female gamete.
Foot: helps to give nutrients to the sporophyte.
Germinating spore: spores that have taken hold and will become new plants.
Leaves: produce photosynthesis, collect water.
Neck canal: route for sperm to travel for reproduction.
Neck wall: creates the neck cavity.
Operculum: breaks when spores are ready to leave and germinate.
Protonema: hormones for new cellular growth.
Rhizoids: specialized root-like structure, anchors the moss but does not absorb water like roots.
Seta: helps transfer nutrients throughout the flower.
Sperm/Antheridium: male gamete.
Spores: type of reproduction from the sporophyte.
Spore case: holds spores.
Sporophyte: creates the spores.
Venter: holds the egg.
Venter wall: creates the venter cavity.
Zygote: single-celled organism created after fusion of the egg and sperm.