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Parts of the flowers and reproduction in plants with seeds
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What is a flower?
• A flower isn´t an ornament or a present for someone, is the reproductive organ of plants.
The function of a flower is to produce seeds for the plant reproduction. For the plants, these seeds are the near generation.
The flower is a
structure made up
of modified leaves.
It contains the
reproductive organs
of the plant where
gametes are
produced.
anther
stamen
petal sepal
stigma
style
ovary
P I S T I L
filament
corolla
calyx
• Pollination: is the transfer of pollen from the anthers of a flower to the stigma of the same flower or of another flower.
• Consists of the union of a male gamete with the female gamete.
• Once a pollen grain reaches the stigma of a flower, it starts to develop a tube (pollen tube), which grows along the style until it reaches the ovary.
• The male gametes travel through the pollen tube to reach the ovary, where the female gamete is.
• Male and female gametes join, fertilization takes place and the zygote is formed.
seed The develop of
the zygote
.
The fruit is formed around the seed in angiosperms: after fertilization , the flower loses the sepals, petals, stamens, style and stigma. The walls of the ovary get “fatter” and form the fruit with the seed inside. The fruit´s function is to protect the seed and help in its dispersion.
• The seed can be dispersed by:
Wind
Animals
……
With this, the plant colonized places.
• If the conditions are good, when the seed fall to the ground will germinate.
• 1º: seed absorbs the water so the coast breaks.
• 2º: seed opens and the embbryo begins to develop creating a new plant.
• At first, the new plant feeds on the supplies stored in the seed until it can carry out photosynthesis and begans to make its own nutrients.
anther
stamen
petal sepal
stigma
style
ovary
P I S T I L
filament corolla
calyx
Bibliography:
• http://www.pollinatorparadise.com/what_is_pollination.htm
• Libro Natural Science bruño 1º ESO
• Libro de Natural Science 2ºESO
• Book of natural Science Anaya 1º ESO
• Unit 6 Natural Science 1º ESO
