Unit 4 – Notes #2 – Non-Vascular Terrestrial Plants
Kingdom: Plantae
Phyla: Bryophyta, Hepatophyta, and
Anthocerotophyta
Members: Mosses, Liverworts and
Hornworts
Typical
Moss
(Bryophyta)
Hornworts
(Hepatophyta)
Liverworts
(Anthocerophyta)
Characteristics of Bryophytes
Pigments:
1) Chlorophyll a
2) Chlorophyll b
-both are green pigments.
Habitat: 1) Can only thrive in wet areas
(swamps, marshes, near streams)
2) Thrive in climates that receive year-round
precipitation; tropical and temperate
rainforests.
A wet environment is crucial for bryophyte
survival:
- As they lack a proper water transport
system (non-vascular).
- No protective surface (waxy cuticle) to
guard against water loss due to evaporation.
- Have flagellated sperm cells that must swim
through water to fertilize eggs. Therefore; No
water = No reproduction.
Morphology: (Form)
- Most look like miniature evergreen trees,
but only a few centimeters tall.
Moss Structure:
- Each moss plant has a thin upright
shoot that looks like a stem with tiny
leaves; these are not true leaves or
stems because they lack proper
transport tubules.
- From the base of the shoot grows a
number of thin branches called rhizoids
that penetrate into the ground and act
like roots to securely anchor the plant.
(they do not help in water transport)
- Water passes from cell to cell through
osmosis. This water transport system is fine
if the organism is small. This is why
bryophytes never grow tall.
Life Cycle:
- Life cycle involves the alternation between a
haploid organism that gives rise to a diploid
organism in the second generation, which
gives rise to a third generation that is haploid
and so on and so on….
- Have female and male gametophyte (1N)
stage, this gametophyte stage produces
haploid gametes (1N) from haploid plants.
These gametes fuse to form a diploid (2N)
zygote which gives rise to diploid sporophyte
(2N) structures including a sporangium.
Meiosis takes place in the sporangium to
produce haploid (1N) spores to germinate
into new gametophyte generation.
Moss Life Cycle: STUDY IT !