Figure 38.2 Review of an idealized flower

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Transcript Figure 38.2 Review of an idealized flower

Figure 38.2 Review of an idealized flower
Pistil
Objective: You will be able to identify
and give the function of the parts of a flower.
Do Now:
• Read pages 612 and 613
• For each part of the flower, write its
function
• This will take you a few minutes
Male parts
• Male part is called the stamen
• The stamen consist of the anther and
filament
• Anther
– Carries out meiosis to make pollen
– Sperm cells are inside the pollen
• Filament
– Holds the anther into the air
Female parts
• Female part is called the pistil
• The pistil is made of the stigma, style and
ovary
• Stigma is sticky to capture the pollen
• Style is a passageway to the ovary
• Ovary
– Carries out meiosis to make eggs
– The eggs are found within ovules
Objective: You will be able to describe
the events of pollination and fertilization.
Do Now:
• Read page 616
• What two things form from fertilization?
Figure 38.5 Pollen grains have tough, ornate, and distinctive walls
Pollination
• Pollination is the transfer of the pollen from
the anther to the stigma
• If the pollen lands on a flower on the SAME
plant it is called self-pollination
– If it lands on a different individual then it is
called cross-pollination
• Pollinators are used to move the pollen
Figure 38.3d1 Pollination modes
Figure 38.1 Simplified overview of angiosperm life cycle
Fertilization
• Fertilization occurs within the ovule
• There are actually two sperm cells
• The first will fertilize the egg and form a
zygote
– This zygote will undergo cleavage to from an
embryo
Fertilization
• The second sperm will fertilize a 2n cell and
form a 3n cell called the endosperm
– The endosperm is the food source for the
embryo
• This concept of two fertilizations is called
double fertilization
• It is unique to flowering plants.
After Fertilization
• The ovule itself will harden and become a
seed
• The ovary itself will change and become a
fruit
– The fruit is used for seed dispersal
Figure 38.12 Development of a pea fruit (pod)
Objective: You will be able to identify
and describe the parts of a seed.
Do Now:
• Read page 618
• Give examples of fruits that everyone thinks
are vegetables.
Figure 38.11 Seed structure
Seed Structure
• The embryo consists of the hypocotyl and
the epicotyl
– Hypocotyl becomes the root
– Epicotyl becomes the leaves and upper part of
stem
• Cotyledon is used as a food source
• The seed coat protects the seed
Seed germination
• Once proper conditions are met, the seed
will start to germinate.
• Seed germination depends on water, oxygen
and temperature
• Why not light?