Fern reproduction

Most ferns reproduce sexually. Dr Leon Perrie from Te Papa discusses the main elements of the reproductive life cycle of ferns. He refers to a diagram of the fern life cycle interactive to illustrate his clear concise explanation.

Jargon alert: Meiosis is a special type of cell division that produces gametes (typically egg and sperm cells in animals or spores in ferns) – these are haploid cells as they have half as many chromosomes as their parent and are specialised for fertilisation. Haploid means having 1 copy of each chromosome. Having a single set of chromosomes. Gametes (egg and sperm cells) are haploid.

Point of interest:

• The fern life cycle diagram featured in this video is an animated interactive. Students can view video clips and images to learn even more about the life cycle process.

• Why is water important for fern reproduction?

Transcript

DR LEON PERRY

Most ferns reproduce sexually, and that involves meiosis and fertilisation. When you are thinking of the typical big fern plant, what it does is, by meiosis, produces spores, and spores have half the number of chromosomes of the big parent plant.

The spores are released into the wind. If the spores happen to land somewhere suitable, they will grow into what is called a gametophyte, and that is a whole separate individual plant. It’s very tiny – maybe the size of your fingernail – and it’s just like a little thin small green plate.

What that does is it will produce the sex cells, the eggs and the sperm. The sperm needs to swim through water in order to get to the eggs. The eggs are housed or maintained in the gametophyte. And that dependence on water is why ferns are so often linked to wet habitats.

If the sperm do manage to get to an egg, fertilisation occurs, and that is where the two, the sperm and egg come together. It doubles the number of chromosomes, and that gives rise to a whole new typical fern plant again, and the cycle repeats.

Acknowledgement: Museum of New Zealand Te Papa Tongarewa