Plant and
FungiReproduction
Campbell 9th Ed
Chapter 38- Plants
Chapter 31- Fungi
Outline
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Formation of Angiosperm Gametes
Pollination
– Self Pollination
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Fertilization
Life Cycle of Plants
Life Cycle of Fungi
Four main groups of
plants
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Moss- No vascular tissue, no seeds
Fern- Vascular tissue but no seeds
Gymnosperm- Vascular tissue and
seeds (ex: pine tree)
Angiosperm- Flowering PlantsVascular Tissue, Seeds and Flowers
All this reflects evolution from ___ to ___
What’s weird about
plant life cycles?
Alternation of generations
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Haploid
Gametophyte
(n)
Mitosis
Spore
Sperm
n n
n n Spores
Meiosis
Spore mother
2n cell
Egg
Gamete fusion
2n
Zygote
2n Embryo
Sporangia
Diploid
Sporophyte
(2n)
What that looks like in
a fern…
Typical Fern Lifecycle
18
Angiosperms
Pathways to Flower
Production

Genetically regulated flowering
pathways
– light-dependent
short-day plants
 long-day plants
 day-neutral plants
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– temperature-dependent

vernalization - period of chilling
Structures- Shown on
next slide
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Female Structures.
– single or fused carpels also referred to as
simple or compound pistils

ovules produced in pistil’s swollen ovary
– style - slender neck
– stigma – pollen receptive structure
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Male Structures
– Stamen- male structures
Anther- pollen producing
 Filament – stalk

Angiosperm Flower
Alternation of
generations in an
angiosperm.
Formation of Angiosperm
Gametes *

All plant sexual life cycles are
characterized by an alternation of
generations.
– Diploid sporophyte gives rise to haploid
gametophyte generation.
Male gametophytes - Pollen grains- microspore
 Female gametophyte - Embryo sac- megaspore
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*This is to help you understand the next
diagram, but not in the scope of testing.
Formation of Angiosperm
Gametes

Pollen Formation
– Microspore mother cells are microspore producing
cells
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Microspores make sperm (Megaspores are female)
– Each pollen sac contains specialized chambers
enclosing microspore mother cells.
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Undergo meiosis to form four haploid microspores.
– Pollen grain shapes are specialized for specific flower species.
– Pollen of some plants causes hypersensitivity response in some
people.
Formation of Angiosperm
Gametes *

Embryo Sac
– Megaspore mother cell found within each ovule.

Undergoes meiosis to produce four haploid megaspores.
– Usually only one survives and the other three are absorbed by
the ovule.
 Remaining megaspore undergoes mitosis and produces
eight haploid nuclei enclosed in an embryo sac.
– *This is to help you understand the next diagram, but not
in the scope of testing.
Pollen Grain and Embryo Sac
Formation
Fertilization

Double Fertilization results in two key
developments:
– Fertilization of the egg.
– Formation of endosperm.

Pollen grains adhere to the stigma and
grow a pollen tube that pierces the
style.
– Grows until it reaches the ovule in the
ovary.
Pollen Tube Formation
and Fertilization
Alternation of
Generations and Fitness
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By alternating, plants can continue
their life cycle even when there is no
reproductive partner.
Spores resist adverse conditions such
as drought, extreme heat, and
extreme cold.

Moss and ferns rely on water for their
swimming sperm
Alternation of
generations in an
angiosperm.
Typical Angiosperm Lifecycle
Diploid
Haploid
36
Seasonal Reproduction
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Plants in N. America can time their
reproduction to give them the best
chance of reproductive success.
Some angiosperms are biennial. They
take two years to go through one
cycle. This may allow them to become
hardier. (They can also change this
timing in response to environment).
Diapause- becoming dormant in
adverse conditions.
Fungi
The Body of a Fungus

Fungi exist mainly in the form of
slender filaments (hyphae).
– long chains of cells joined end-to-end
divided by cross-walls (septa)
rarely form complete barrier
 cytoplasm freely streams in hyphae
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– mycelium - mass of connected hyphae
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grows through and penetrates substrate
What’s weird about
fungi reproduction?
How Fungi Reproduce
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Differ from most animals and plants in that
each compartment of hypha can contain one,
two or more nuclei
– monokaryotic - each compartment has a single
nucleus
– dikaryotic - two distinct nuclei within each
hyphae compartment
How Fungi Reproduce
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Fungi are capable of both sexual and asexual
reproduction.
– Fungi reproduce sexually after two hyphae of
opposite mating type fuse.
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Some fungi have dikaryotic stage (1n + 1n) before
parental nuclei fuse to form diploid nucleus
Ascomycota
Sordaria- Remember this
slide from the meiosis lab?
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You are looking at a fungus,
Sordaria
The structures you see are
called asci (ascus- singular),
they are the product of
meiosis.
Count 50 asci. Tally the
number that show
crossover/ no-crossover.
Divide the crossover
frequency by 2 to get map
units (centimorgans).
Basidiomycota
Metabolic Pathways of
Fungi
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Anaerobic fermentation provides flavor
for wine and cheese.
Biochemical manufacturing of organic
substances
– food
– pharmaceuticals
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Yeasts break down carbon-containing
products.
– bioremediation
Ecology of Fungi
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Fungi and bacteria are the principal
decomposers in the biosphere.
– mineral cycling
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Fungi are virtually the only organisms capable
of breaking down lignin- (found in wood).
Fungi often act as disease-causing
organisms for both plants and animals.
– agricultural damage- corn rust (also
wheat rust, rye rust), potato blight
– human health
Ecology of Fungi
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Mutualistic associations
– lichens - fungi and green algae
Mutual relationship
 Primary succession
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– mycorrhizae - fungi and plant roots
Mutual relationship may be food protection
 Fungi on root may help plant absorb water/
minerals
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