Title: Life Cycle - in a nutshell - bryophyte
Headings: Life cycle
Life cycle
... life cycle in a nutshell.
Spore to protonema
The following stylized diagrams show some of the variations.
Further gametophyte growth
Some interesting links

Content: Life Cycle - in a nutshell - bryophyte




Life cycle
This page will start with the bryophyte...
... life cycle in a nutshell. A bryophyte spore is haploid. A haploid cell has one set of chromosomes, a diploid cell has two. In humans, the egg and sperm cells are haploid. When they unite, the resulting cell is diploid and the ensuing embryo continues its development as a diploid individual. Each parent has contributed one set of chromosomes. A bryophyte spore germinates and produces an often algal-like mat, called a protonema (plural protonemata) and the leafy or thalloid stage of the gametophyte develops from the protonemal stage. The protonemata are almost always ephemeral but there are exceptions. Amongst the mosses there is a small number of species in which the protonemata are persistent and the leafy plants are ephemeral. The spore was haploid and so are the resulting protonema and the ensuing leafy or thalloid stages.