Moss Life Cycle
Alternation of generations
Zygote
created
from egg
& sperm
Alternation of generations
Zygote divides
by mitosis to
create adult
sporophyte
Alternation of generations
Haploid
spores
created by
meiosis
Alternation of generations
Haploid spores
released into air
Alternation of generations
Female
gametophyte
creates eggs
Spore grows into
male or female
gametophyte
Male
gametophyte
creates sperm
Alternation of generations
Sperm & egg
create diploid
zygote
Alternation of generations
Cycle
repeats
Group 1: Seedless, Nonvascular Plants
• Most primitive of
plants
• Live in moist
environments
– Swimming
sperm
• Examples:
– Liverworts
– Hornworts
– Mosses
Mosses
• Because
nonvascular: Grow
low to ground
– Water transported by
simple diffusion
• Lack true leaves
– only 1 cell thick
• Rhizoids anchor
into soil
• Early inhabitant of
new ecosystems
(succession)
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
Male
gametophyte
(creates
sperm)
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
– Sperm swims through
water to fertilize egg
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
zygote
Male
gametophyte
(creates
sperm)
• Gametophyte stage
– Sperm swims through
water to fertilize egg
Female
gametophyte
(creates
eggs)
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
stalk
zygote
– Sperm swims through
water to fertilize egg
• Sporophyte stage
– Stalk grows out of the
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
capsule
stalk
zygote
– Sperm swims through
water to fertilize egg
• Sporophyte stage
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
– Stalk grows out of the
zygote
– Haploid spores created
inside capsule by meiosis
Moss Life Cycle
capsule
stalk
zygote
..
• Gametophyte stage
– Dominant stage; Haploid
– Looks like mat of green
shag carpet
• Antheridium: produces
male sperm
• Archegonium: produces
female egg
– Sperm swims through
water to fertilize egg
• Sporophyte stage
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
– Stalk grows out of the
zygote
– Haploid spores created
inside capsule by meiosis
– Spores released and
grow into new
gametophytes
See appendix B in your text book
Moss Life Cycle
capsule
stalk
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
.
(creates
sperm)
Female
gametophyte
.
(creates
eggs)
See appendix B in your text book
Moss Life Cycle
capsule
stalk
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
See appendix B in your text book
Moss Life Cycle
capsule
stalk
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
See appendix B in your text book
Moss Life Cycle
capsule
stalk
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
capsule
stalk
zygote
sporophyte
zygote
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
capsule
stalk
.
zygote
sporophyte
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Male
gametophyte
(creates
sperm)
Female
gametophyte
(creates
eggs)
Moss Life Cycle
Place the steps of the moss life cycle in
order, from the step started for you:
__ 1___ Spores land.
5
_______
Diploid sporophyte will grow from zygote.
3
_______
Through water, sperm swim from
antheridium (male gametophyte) to
archegonium (female gametophyte).
2
_______
Moss gametophytes grow near the ground.
6
_______
Sporophyte will create and release spores.
4
_______
Fertilization occurs.
Plant Life Cycle Comparisons
Plant type
Sporophyte
Gametophyte
Dominant?
Moss
Stalk with cup
(capsule) at tip,
which is where
spores are
produced.
More familiar,
carpet-like plant
that produces
specialized
gametes
GAMETOPHYTE
Fern
More familiar,
leafy plant with
clusters of spore
producing sacs
(sori)
Haploid plant
body (prothallus)
is size of a finger
nail, produces
both male and
female parts
SPOROPHYTE
Conifer
More familiar- like
pine trees,
produces male
and female cones
that produce
spores
Pollen grains are
male
gametophytes
sperm, female
gameotphytes are
microscopic
eggs
SPOROPHYTE
Review
1)
2)
3)
4)
5)
6)
Label the parts of the diagram.
Using the picture answer the
following:
•
Where are spores created?
•
Name the haploid stage.
•
Which grows from the zygote?
How are the antheridia and
archegonia different? Similar?
Meiosis begins which stage of
plants?
Fertilization begins which stage of
plants?
How are haploid spores created?