Bryophytes Flashcards
(24 cards)
What are bryophytes?
non-vascular plants that rely on cell to cell transport, have no true roots, xylem or phloem. can’t transport essential products far so are close to the ground
3 types of bryophytes
Mosses, Liverworts, Hornworts
Bryophyte dominant life stage
Gametophyte (n)
What do gametophytes produce?
male and female gametes (n) through mitosis
Are bryophytes heterospory?
No, either male or female
Antheridium
produces and contains sperm in non-flowering plants
Archegonium
produces and contains eggs in non-flowering plants
Why is water essential for bryophytes?
sperm is flagellated so travels through water to reach the female plant
Do male or female bryophytes produce sporophytes?
only female bryophytes as sporophytes only grow from the archegonium
gametes (n) to sporophyte (2n) process, bryophytes
Fertilisation, produces a zygote which grows into a sporophyte
the archegonium receives the sperm
Is the sporophyte dependent on the gametophyte in bryophytes?
yes
Sporophyte (2n) to spores (n) process, bryophytes
meiosis, produces spores that are a single, tough cell
Spore dispersal, bryophytes
spore capsule breaks open, dispersal via wind
when spore lands in favourable conditions it germinates and grows into the gametophyte
Parts of sporophyte and how they encourage dispersal
Seta (stem) and capsule on top
Seta elongates, capsule opens
NZ mosses
over 500 mosses in NZ, around 100 endemic
Sphagnum
plant that makes up peat moss
Common in dense colonies, holds water and acidifies soil
What are peat bogs?
Wetlands full of partially decaying vegetation like sphagnum
How does moss react to extreme conditions?
can ‘shut down’ in extreme conditions, becoming dormant until conditions are favourable
have slow and low growth, with low light requirements and can asexually reproduce
Liverworts
can be thalloid or leafy
different to moss in structure and spore dispersal
How do liverworts asexually reproduce?
Gammae cups, when rain drops into cups, pieces of tissue splash out and land in favourable conditions and germinate
Hornwarts
Least common bryophyte
How do bryophytes survive conditions?
Waxy cuticle to retain water and protect
Stomata allowing gas exchange and closes to prevent loss
Gametangia and Sporopollenin
Gametangia and Sporopollenin
protect reproductive areas and spores
What causes the transition from bryophytes to pteridophytes?
Formation of xylem and phloem
