Studied by 3 people
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Bryophytes
Land plants without vasculature or seeds
Bryophyte morphology
Thalloid structure, undifferentiated not organized into tissues or organs, lack stomata but have pores
Rhizoids
No vasculature, simplified root structure from epidermal cells, rows of cells extend into growing media for nutrients and anchoring
Nutrient transport between cells
Use demotubule from ER of one cell to ER or another and plasmodesmata
Reproduction
Gametophyte (n) stage is dominant, gametes are produced in this stage and they come together to form sporophyte (2n)
Asexual reproduction
Fragmentation, gemmae (liverwarts and mosses) multicellular make more gametophytes, don’t produce asexual flagellated zoospores
Life cycle marchantia spores (n)
Gametophyte stage begins with meiosis and spores (n) grow into male or female gametophytes
Life cycle marchantia gametophyte (N)
Male gametophytes produce reproductive structure antheridia (sperm) and female produce archegonia (egg), sperm requires moisture to swim to egg
Antheridia
Spherical/elongated, sterile cell layer houses spermatogenous cells, biflagellated
Archegonia
Flask shaped, long neck swollen base, Venter houses single egg, releases chemicals that attract sperm to swim down canal
Life cycle zygote (2n)
Fertilization requires water medium, motile sperm cells swim to eggs and produce zygote which developed in venter
Matrotrophy
Maternal gametophyte nourishes the zygote
Embryophytes
Multicellular embryo is housed within female gametophyte
Life cycle sporphyte (2n)
Sporophyte develops in calyptra and is produced by zygote mitosis. Placenta acts as interface between sporophyte and gametophyte
Life cycle Mature sporophyte
Once mature meiosis happens producing genetically diverse haploid spores, the calyptra ruptures releasing the spores from the archegonia
Marchantiophyta (liverwarts)
Two main clades: complex thalloid liverwarts (marchantia), leafy or simple thalloid
Riccia, simple liverwort
Dichotomous branching, sporophyte embedded within gametophyte in sphere capsule
