Introduction to Plant Reproduction

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Transcript Introduction to Plant Reproduction

Introduction to Plant
Reproduction
Objectives:
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Distinguish between asexual and sexual
reproduction of plants;
Discuss importance of both types of
reproduction in plants;
Identify major parts of seeds;
Describe process of seed germination.
Define Propagation
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Propagation
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The reproduction of plants either sexually or
asexually.
Asexual vs. Sexual Reproduction
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Asexual reproduction involves ONE living
organism.
Sexual reproduction involves TWO living
organisms. *Male and Female* Can be on
one plant.
Define sexual reproduction
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Sexual Reproduction:
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The union of the female and male sex cells to
produce a seed (embryo).
Ovule: female sex cell.
 Pollen: male sex cell.
 Embryo (seed-germ): an immature plant.
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*Sexual reproduction involves the creation of
a genetically new individual.
Define asexual reproduction
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Asexual Reproduction:
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The reproduction of a plant without the uniting
of a pollen and ovule.
Asexual reproduction is often referred to as
vegetative propagation since no seed is involved
in the formation of the new plant.
It is known as a clone.
Leaves, stems or roots may be used to grow a
new plant.
*Produces a genetically identical plant.
BRAINSTORM
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Group A: Brainstorm benefits of asexual
reproduction of plants (i.e. vegetative
propagation)
Group B: Brainstorm benefits of sexual
reproduction of plants (i.e. seeds)
Benefits of Asexual Reproduction
(Vegetative Propagation)
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True traits of the parents
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No seed
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Maintains genetic purity with
100% replication of parent plant.
Some plants do not produce a seed or the seeds are
too small to work with.
Accelerates the time it takes to get a new plant to
the market
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Traditionally, it would take up to 40 years to get a
new plant to the general public; however,
micropropagation can yield marketable levels of
plants within 8 to 12 years.
Benefits of Sexual Reproduction
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Genetically new individual created
Hybrid created
Potential to improve crop traits
Seed can be stored
Types of seeds.
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Monocots:
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Seeds with one seed leaf
Dicots
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Seeds with 2 seed leaves or 2 cotyledons
Monocots
Dicot
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Parts of a Seed
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Embryo Plant = will become seedling plant
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Cotelydon(s)
Primary Root (Radicle)
Embryonic (seed) leaves
Endosperm = stored food
Seed coat = protective shell
Label a Lima Bean
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Cut:
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Carefully cut the lima bean in half;
Place the halves on the paper plate.
Label:
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Cut and label tags from the sticky-notes;
Stick each label on its own pin;
Place the labeled pins in the correct part of
the seed.
Pollination, Fertilization and
Germination
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Pollination
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Fertilization
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The transfer of pollen
from an anther to a
stigma of a flower of
the same species.
The union of the pollen
and ovule cells.
Germination
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The sprouting of a
seed.
Germination
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Process by which an embryo plant inside
the seed changes into a developing
seedling.
Germination is the end of the period of
dormancy
Favorable conditions are present for the
growth and development of the seedling
plant…so it sprouts and starts to grow!
Seed Germination Test
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The germination rate is a measure of viable
seed, or the percentage of seeds planted
that sprout. To calculate:
The number of live seeds
divided by
the number of seeds planted
equals
the germination rate.